Moparts

Safely Wiring Accessories/Amp Gauge Re-wire

Posted By: jcruse64

Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 12:05 PM

Taking the dash cluster apart on my '73 W200. Replacing missing bulb sockets and changing to LED's, cleaning it all up,and painting the gauge needles. My Amp gauge looks to be in fine shape, and I can find no signs that it's gotten too hot. Will also be taking the bulkhead connectors apart and cleaning them up and packing with grease.

I've been reading through a ton of the older posts on how to make the amp gauge safe for the vehicle, as now is a good time to do any modifications to make it so. I'd rather keep the amp gauge functional, to watch how the battery is doing. I understand that if I simply add a wire from the alt stud, with a suitable FL, to the stater relay batt stud, this will reduce load on wires passing through the bulkhead connectors, but will make the amp gauge inaccurate. If I run the "parallel" setup, per Nacho, since ALL leads are going to/from the amp gauge, the amp gauge should still render accurately, correct??

I also get it about the advice to NOT run any accessories or other powered items (think headlights run on a relay setup), except for maybe a winch, from the battery side, but to instead run them from the alt side. Where would i actually run wire off of to accomplish this, then? Right off the alt stud? I'm already running Crackedback's headlight relay system off the stud; there's not a lot more room if I end up doing a relay for the blower motor, and any other lights or accessories I might want. Should I run a wire off the alt stud to a power distribution block, and then power my headlight relays, blower motor relays, and other accessories off that? Do I run it off the battery stud on my starter relay, or is that considered running off the battery? Also looking at converting my cigarette lighter to a USB port, per E'berg's article in prior Mopar Action, and have picked up a USB outlet that also displays system volts.

Thank you,

Joe
Posted By: jbc426

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 01:15 PM

The goal I use when wiring a classic Mopar is to keep any high amperage current drawing devices from passing through the bulkhead connector. I follow a modified Mad Electric method of accomplishing this. I also run a fused properly routed cable from my alternator output terminal to my 12V+ starter relay lug, and I bolt both Amp gauge wires to on side of the amp gauge.

I often install a volt gauge so I can verify charging when the car is running. Your stock amp gauge is ok to use if you can't stand not having your gauge work, but don't run more than your fatory amp load through it. The secondary cable from the alternator to your 12V+ starter lug will keep the high amp 12V+ charging current load out of your bulkhead connector.

Anything that uses more than 10 amps gets properly fused and has relays installed on the circuit. I power the relays through a 12V+ distribution lug located in the engine compartment, and that is often the starter relay lug. Of course, the typically 4 gauge cable from the starter relay to the battery continues the current flow from the alternator to the battery.

Also, I use Marine Grade components for any fusing, relay or wiring applications, high quality electrical tape and heat shrink tubing. I solder all my connections, but properly done crimp connectors work very well too.
Posted By: Sniper

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 01:57 PM

Originally Posted by jbc426
The goal I use when wiring a classic Mopar is to keep any high amperage current drawing devices from passing through the bulkhead connector. I follow a modified Mad Electric method of accomplishing this. I also run a fused properly routed cable from my alternator output terminal to my 12V+ starter relay lug, and I bolt both Amp gauge wires to on side of the amp gauge.

I often install a volt gauge so I can verify charging when the car is running. Your stock amp gauge is ok to use if you can't stand not having your gauge work, but don't run more than your fatory amp load through it. The secondary cable from the alternator to your 12V+ starter lug will keep the high amp 12V+ charging current load out of your bulkhead connector.

Anything that uses more than 10 amps gets properly fused and has relays installed on the circuit. I power the relays through a 12V+ distribution lug located in the engine compartment, and that is often the starter relay lug. Of course, the typically 4 gauge cable from the starter relay to the battery continues the current flow from the alternator to the battery.

Also, I use Marine Grade components for any fusing, relay or wiring applications, high quality electrical tape and heat shrink tubing. I solder all my connections, but properly done crimp connectors work very well too.


If you properly wire the vehicle the only load passing thru the ammeter is what is needed to charge the battery. Nothing else. So it really doesn't matter how much capacity you alternator has or how much load you've put on the system. I just finished converting my 51 Plymouth to 12v and rewiring the vehicle. Still running the stock, original ammeter. Because the only load passing thru my ammeter is the charge for the battery, nothing else. As per the factory.
Posted By: RapidRobert

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 03:19 PM

To keep the ammeter functional NOTHING can be tapped into the line between the battery & the ammeter (including starter relay batt stud) cuz if you do you would be takeing current out of the battery without it showing on the ammeter as the ammeter strickly shows current going past the ammeter that is going into or out of the battery so you are cheating the gauge reading. #1 #1 #1 do Nachos bulkhead parallel bypass on the 2 main in/out heavy current wires & leave several inches of those 2 wires behind the bulkhead so if you have to seperate the bulkhead again, pulling the front half forward you can do so (clean all bulkhead terminals when you are in there). With this done you can add your switched draws to the alt batt stud (relay high current ones that have larger wires so you ain't running alot of large wires everywhere) or under the hood (depending on where your devices are located) between the ammeter downstream to the bulkhead (& actually between the "welded splice" where the wires down stream from the ammeter between it & the bulkhead T off to power the fuses/horn/column etc as is a bit better as it is slightly closer to the alt & you're going thru less "connections/terminals" tho a moot point if ALL terminals/connections are cleaned & have minimal voltage drops. EDIT short version: Do Nachos bypass/clean all terminals & connections/add or relay devices to alt or down stream from the welded splice. MORE EDIT I reread & yes you can run from the alt to a distribution block & use it as your power take off. the alt is the power source so as close to that as possible is a good plan
Posted By: larrymopar360

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 03:26 PM

You've gotten the advice you need on wiring. I just want to add something on painting needles. It can be done but it's a difficult job IMO. Any misstep and you're in trouble, and I don't think they ever look right. You can find NOS ones still for around $50, except the speedometers which run quite a bit more. Occasionally see a KPH one on ebay for $95 if you don't mind that. It's for a later truck going 140 kph/85 mph.

KPH

https://www.ebay.com/itm/NOS-MoPar-...Ramcharger-Speedometer-KPH/143411475638?
Posted By: therocks

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 04:38 PM

Ive had at ;east 10 older Rams.Every one had some burning on the Amp gauge.Had 2 or 3 at least that would cut out because they were so bad.I bypassed all of them and just installed a volt gauge.I ever get another Ill do the same.Rocky
Posted By: larrymopar360

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 05:49 PM

Originally Posted by therocks
Ive had at ;east 10 older Rams.Every one had some burning on the Amp gauge.Had 2 or 3 at least that would cut out because they were so bad.I bypassed all of them and just installed a volt gauge.I ever get another Ill do the same.Rocky
I just bypassed mine and haven't run a volt gauge but I did install a Quality Power alternator, 150amp, so I should be good for awhile. I just prefer the look of all stock. I still have the dead amp gauge in it's pod.

All NOS gauges. All working except amp.

Attached picture NOSgaugesPW.JPG
Posted By: T2R9

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 06:16 PM

On my 78 I changed the amp gauge to a volt gauge. Alt go's to the starter relay and from the starter relay to a bus bar under the dash that distributes the power as needed.

Attached picture IMG_0779 (Medium).JPG
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 06:52 PM

Originally Posted by RapidRobert
To keep the ammeter functional NOTHING can be tapped into the line between the battery & the ammeter (including starter relay batt stud) cuz if you do you would be takeing current out of the battery without it showing on the ammeter as the ammeter strickly shows current going past the ammeter that is going into or out of the battery so you are cheating the gauge reading.

Only when the engine is off or the alternator can't generate enough power.

When the alternator is producing enough power to supply a device tapped in at the battery, then the power passes through the ammeter.
Current flows from the highest voltage. So unless there is a ton of resistance in the line, when the alternator is running, system voltage is around 14 V.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 07:19 PM

Originally Posted by jcruse64
I'd rather keep the amp gauge functional, to watch how the battery is doing. I understand that if I simply add a wire from the alt stud, with a suitable FL, to the stater relay batt stud, this will reduce load on wires passing through the bulkhead connectors, but will make the amp gauge inaccurate. If I run the "parallel" setup, per Nacho, since ALL leads are going to/from the amp gauge, the amp gauge should still render accurately, correct??

Correct. I don't have a truck service manual, but the '73 Dodge cars FSM shows two versions of that type of bulkhead bypass that retains the ammeter function.
See if there was a optional wiring arrangement for the trucks, or take some ideas from the Dart or Charger/Coronet versions.

Quote

I also get it about the advice to NOT run any accessories or other powered items (think headlights run on a relay setup), except for maybe a winch, from the battery side, but to instead run them from the alt side. Where would i actually run wire off of to accomplish this, then? Right off the alt stud? I'm already running Crackedback's headlight relay system off the stud; there's not a lot more room if I end up doing a relay for the blower motor, and any other lights or accessories I might want. Should I run a wire off the alt stud to a power distribution block, and then power my headlight relays, blower motor relays, and other accessories off that? Do I run it off the battery stud on my starter relay, or is that considered running off the battery? Also looking at converting my cigarette lighter to a USB port, per E'berg's article in prior Mopar Action, and have picked up a USB outlet that also displays system volts.


Joe, cant help you on the cig lighter.
Winches are a special problem and I don't know the best answer (other than a PTO laugh2). If its going to draw a lot of current under load (check the specs), it might be more than the alternator can produce, especially at slow idle. I suspect this is why power for plows and winches were often tapped in at the battery. This probably contributed to the melting of a fair number of 70s era ammeters. Alternator is sending all it can to the winch through the ammeter, and when votlage drops to 12.8 - 13, then the battery sends whatever is needed. As the electric load is reduced, the alternator can provide the recharge. And its probably a big recharge, battery could be sucking 30 amps for a few minutes through the ammeter and all the charge wires.

As far as connecting in more normal accessories to be used with engine running, a power distribution block is a good idea.
It could just be a single stud terminal strip, or an auxilery fuse/breaker box.
Running it off the starter relay stud is the same as running it off the battery - you are correct.

On the Abody version, I beleive the factory eliminated the standandard alternator output wire, but you could leave. That would be the 'Nacho' parallel feed.
On the Bbody version, they added two terminal blocks and the ammeter's original wires had to be eliminated. The reason for disconnecting them is to insure that in case of a short to ground, the battery would send current through the 16 gage fusible link. The link at the starter relay is too big to protect the smaller wires inside the cab.

Attached picture 1973-60Amp-Dart-color2.png
Attached picture 1973-65Amp-Charger-Cornet.png
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 08:06 PM

Maybe this makes it clearer.
The original red (battery) wire from the bulkhead to the ammeter can be removed.
The original alternator connection from main splice to ammeter can be removed and taped off;
Or can be removed and connected as the new feed through a grommet. That might be a better connection than the bulkhead connector.
I say might, because some years and models and options had better bulhead connectors for the main feeds. I don't know what your truck has.

Attached picture 1973-60Amp-Charger-Cornet-color3.png
Attached picture 1973-60Amp-charger-Cornet-color4.png
Posted By: Jim_Lusk

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 11:26 PM

I'm working on my '67 Barracuda wiring and have bypassed most of the charge current through a wire from the alt to the battery, BUT I also fused this leg with a maxi fuse. I also replaced the fusible link going into the bulkhead with a maxi fuse. I will add a volt meter of some sort before the car hits the road. That will likely be a cig lighter replacement that has two USB charge ports and an LED volt meter.
Posted By: JonC

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/20/19 11:58 PM

A voltage gauge will not verify charging.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/21/19 12:56 AM

Originally Posted by JonC
A voltage gauge will not verify charging.


If Jim, or I, were to run a USB plug w/ voltage readout wired off the alternator, with it's own fuse and a ground, it WOULD read the alternator's volts though, correct?

And when I mentioned I was going to do this USB/volt readout plug at the old cigarette lighter, I should have been clear and mentioned that I was NOT planning on wiring it up with the wiring from the cigarette lighter; sorry about that. I will safely cap that cigarette lighter power lead off.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/21/19 01:11 AM

Originally Posted by jbc426
Anything that uses more than 10 amps gets properly fused and has relays installed on the circuit. I power the relays through a 12V+ distribution lug located in the engine compartment, and that is often the starter relay lug. Of course, the typically 4 gauge cable from the starter relay to the battery continues the current flow from the alternator to the battery.


JBC, this is what I'd like to do, also, except for this; if I've read correctly, running a 12V+ distribution lug off the starter relay lug would mean you're powering these off the battery, and what I've read is that you need to power any added accessories off the alternator, so that you're not discharging the battery any further. I'm not talking about anything factory, like factory radio. Instead, I'm thinking aftermarket stereo amp, a light bar, a CB radio, a power/USB plug. Also not talking about a HEAVY draw item like an add-on, non-PTO winch ( I see where many folks run a 2nd battery under the hood for something like running winches or electric plows).

On this '73, the PO had the truck for probably 30+ years. It ran a plow. He was a mchinist by trade, and built his own Holmes wrecker boom for this 3/4 ton truck. He put another relay next to the starter relay on the fender, and ran a power wire from the starter relay stud to this new relay to power it. This would have been powering it on the battery side, if I follow correctly. From this new relay, he powered the big winch that ran his wrecker boom, and also his plow. Given the high draw, that makes sense to me to power it that way, off the battery. I'm not running either of those on this truck now, and have removed that relay and wiring.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/21/19 02:00 AM

Mattax, thanks for the replies. I think I see "it", on that 2nd post and diagrams.

Amp gauge to battery: From factory: wire coming amp gauge, through bulkhead connector, to starter relay with a FL on it, and then on to the battery with a HEAVY cable to the positive battery post. New way, a solid wire from amp gauge, NOT through bulkhead connector, to the starter relay, then another, same size wire to a single terminal block, and from that single terminal to the battery positive post with a FL. My first question here is, what size wires at these points and what size FL going to the battery. 2nd question on this is, how can I get my head past not having a huge cable connected to the battery post, lol.

Alt to amp gauge: From factory, wire from alt stud, through bulkhead connector. Welded splice of cab side sees power to key, headlights, and accy, with main wire continuing on to Amp gauge. New way, wire from alt stud to another single terminal block. From here, one wire continues to the amp gauge, NOT through the bulkhead connector. At the single terminal block, a fusible link goes to the spot on the bulkhead connector that was formerly occupied by the original line from the alt stud. On the cab side of the bulkhead, the wire past the welded splice is taken off that side of the amp gauge and capped and protected.

Am I close, lol.

I was reading this thread, which you have referenced in other posts here on amp gauge issues:

http://www.dodgecharger.com/forum/index.php/topic,33574.0/all.html

Last page has some good stuff on it, including Nacho's latest idea to implement on this. I was wondering how member PocketThunder's fix got power to the key, headlights, and accy????

Thanks to all of you who are replying. I'm a novice on pretty much everything, and wiring is a bit intimidating. But I want to learn it, and will be completely re-wiring a '76 RC with a modern kit, some day.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/21/19 02:02 AM

Oh, and is it safe to say I COULD run my headlight relays off a power distribution bar that gets its power from the alt stud, or would I need to leave those headlight relay power feeds ON the alt stud. I would think that it would not matter, but I am not sure.
Posted By: jbc426

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/21/19 04:16 AM

Originally Posted by jcruse64
Originally Posted by jbc426
Anything that uses more than 10 amps gets properly fused and has relays installed on the circuit. I power the relays through a 12V+ distribution lug located in the engine compartment, and that is often the starter relay lug. Of course, the typically 4 gauge cable from the starter relay to the battery continues the current flow from the alternator to the battery.


JBC, this is what I'd like to do, also, except for this; if I've read correctly, running a 12V+ distribution lug off the starter relay lug would mean you're powering these off the battery, and what I've read is that you need to power any added accessories off the alternator, so that you're not discharging the battery any further. I'm not talking about anything factory, like factory radio. Instead, I'm thinking aftermarket stereo amp, a light bar, a CB radio, a power/USB plug. Also not talking about a HEAVY draw item like an add-on, non-PTO winch ( I see where many folks run a 2nd battery under the hood for something like running winches or electric plows).



I run a fused heavy gauge cable directly from my alternators to the starter relay. Consequently, the alternator powers any heavy load. I leave the factory wiring that goes from the alternator, through the bulkhead through the amp gauge and back out through the bulkhead to the battery. I regularly bypass the amp gauge by bolting the two wires onto one of the amp gauge studs.
Posted By: Jim_Lusk

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/21/19 04:21 AM

Originally Posted by jcruse64
Originally Posted by JonC
A voltage gauge will not verify charging.


If Jim, or I, were to run a USB plug w/ voltage readout wired off the alternator, with it's own fuse and a ground, it WOULD read the alternator's volts though, correct?

And when I mentioned I was going to do this USB/volt readout plug at the old cigarette lighter, I should have been clear and mentioned that I was NOT planning on wiring it up with the wiring from the cigarette lighter; sorry about that. I will safely cap that cigarette lighter power lead off.


Nothing wrong with running it off the cig lighter circuit, unless it is not switched. We run a similar unit in our late model vehicles, but it just plugs into the cig lighter. As long as you read something above battery voltage you are charging (as long as there isn't something else wrong in the wiring). That's why my charge circuit is fused to the battery and the battery fused into the passenger compartment. I'll draw out my charge circuit one of these days.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/22/19 02:12 AM

Originally Posted by jcruse64
Mattax, thanks for the replies. I think I see "it", on that 2nd post and diagrams.

Amp gauge to battery:
From factory: wire coming amp gauge, through bulkhead connector, to starter relay with a FL on it, and then on to the battery with a HEAVY cable to the positive battery post.
New way,
a solid wire from amp gauge, NOT through bulkhead connector, to the starter relay, then another, same size wire to a single terminal block, and from that single terminal to the battery positive post with a FL.

My first question here is, what size wires at these points and what size FL going to the battery.

The '73 Coronet optional wiring used 6 gage wires protected by a 10 gage fusible link.
Generally fusible links are chosen to be 2 sizes smaller than the weakest wire being protected.
6 gage is huge. I don't know if that's an error in the manual since I haven't seen this option in real life.
Notice the oddly designated battery to starter cable in the Dart wiring diagram. 6B RED Mistake or not? Maybe it means standard was Black and optional was Red. Or its black with red stripe.

When looking at most Chrysler wiring diagrams the wire identification works like this:
Code for circuit - Wire size and then Color code.
A is usually Battery connections
R is Alternator
J is 'Ignition' which also includes other things that are on when the engine is running.
Q is Accessory

[/quote]
2nd question on this is, how can I get my head past not having a huge cable connected to the battery post, lol.
[/quote]
Not sure what you mean here.
The positive cable should have a very wire (4 gage or 2 ga) to the starter and a somewhat heavy wire to the stud on the starter relay.
A 10 gage fusible link is a larger wire than many cars came for the battery feed. Its going to take a lot of amps to melt that! If you go that large, I'd suggest looking for a protective insulating shield for the relay. Stock on many models/years but often gets lost.
Quote

2nd question on this is, how can I get my head past not having a huge cable connected to the battery post, lol.

Not sure what you mean here.
The positive cable should have a very wire (4 gage or 2 ga) to the starter and a somewhat heavy wire to the stud on the starter relay.
A 10 gage fusible link is a larger wire than many cars came for the battery feed. Its going to take a lot of amps to melt that! If you go that large, I'd suggest looking for a protective insulating shield for the relay. Stock on many models but get lost.

Quote

Alt to amp gauge:
From factory, wire from alt stud, through bulkhead connector. Welded splice of cab side sees power to key, headlights, and accy, with main battery wire continuing on to Amp gauge.
New way,
wire from alt stud to another single terminal block. From here, one wire continues to the amp gauge, NOT through the bulkhead connector.
At the single terminal block, a fusible link goes to the spot on the bulkhead connector that was formerly occupied by the original line from the alt stud. On the cab side of the bulkhead, the wire past the welded splice is taken off that side of the amp gauge and capped and protected.

Am I close, lol.

Yes. Exactly. That's what was done for Coronet's with the optional high output alternator.

The terminal block with the arrow pointing to it would be a reasonable location to add an auxilery fuse or breaker box.

But, if the loads you will be adding will be in the passenger compartment (and not using relays), then the factory bulkhead connecting terminals may be too small for the alternator output.
This where an exact diagram for your rig would be really helpful. Or maybe its obvious when you look at the firewall.
For example,in A-bodies around '75 and certainly in '76, the alternator output had a welded splice junction on the engine side which split the power before going through the bulkhead connector.
The same concept might have been introduced earlier on intermediates, full size or trucks.

The '73 Dart optional wiring is a little simpler to implement, and you could add a terminal block anywere in the alternator line.
Hope that makes sense.

yes Nacho is the guy who I credit for helping me understand how this worked!

Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/22/19 12:59 PM

Mattax, thank you for the reply.

"Not sure what you mean here. The positive cable should have a very wire (4 gage or 2 ga) to the starter and a somewhat heavy wire to the stud on the starter relay. A 10 gauge fusible link is a larger wire than many cars came for the battery feed. Its going to take a lot of amps to melt that! If you go that large, I'd suggest looking for a protective insulating shield for the relay. Stock on many models but get lost."

On my '73 truck, the Red, positive battery cable runs from the pos battery post to a lug on the starter relay, and then a similar sized cable runs from relay to the starter. So on your diagram, I just saw a FL going from battery pos post to a termial block, and from there, a wire to the starter relay.

From looking at your diagrams and Nacho's work, I was looking at just running one RED wire from amp gauge stud to the starter relay, with a FL in it before the starter relay. Then keep the same heavy battery cable I already have in place from the starter relay to the pos battery post.

I have a FSM for the truck, as well as a stand-alone wiring diagram; I'll look at it today to see if it offered an alternative routing, like you have shown.

"The terminal block with the arrow pointing to it would be a reasonable location to add an auxilery fuse or breaker box. But, if the loads you will be adding will be in the passenger compartment (and not using relays), then the factory bulkhead connecting terminals may be too small for the alternator output.This where an exact diagram for your rig would be really helpful. Or maybe its obvious when you look at the firewall. For example,in A-bodies around '75 and certainly in '76, the alternator output had a welded splice junction on the engine side which split the power before going through the bulkhead connector. The same concept might have been introduced earlier on intermediates, full size or trucks.The '73 Dart optional wiring is a little simpler to implement, and you could add a terminal block anywere in the alternator line."

Just looking at the engine bay, not sure if the line from the alternator splits off that welded splice on the engine side or not, but I'll will check it out. At any rate, I think I will work out placing an auxilliary power terminal with the feed coming off the alternator stud. Anything I'd run on that (USB power port, extra lights, CB) WILL be fused. Not planning on putting the wrecker boom/winch back on the truck, and no plans to add a winch, but if I did, I'll power it from the battery.

It also sounds, from all the reading I've been doing, like it's not a bad idea to put in a higher output alternator. The one on it is stock. Even with crackedback's headlight relay added on, the headlights dim at idle.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/22/19 06:32 PM


On my '73 truck, the Red, positive battery cable runs from the pos battery post to a lug on the starter relay, and then a similar sized cable runs from relay to the starter.

Maybe it has a remote starter solenoid relay.
I think Chrysler used them late 50s early 60s for cars. Ford and at least some AMC/Jeeps used them in the 70s and 80s. Actually some of the last years of the SJ Jeeps had both a Chrysler type starter relay and the Ford type starter solenoid - maybe around 89 - 90. I think 91 it got different starter with an internal solenoid like our cars have.


I have a FSM for the truck, as well as a stand-alone wiring diagram; I'll look at it today to see if it offered an alternative routing, like you have shown.
if you can also take some photos and post (or e-mail), that would be super.

I doubt the USB or CB is a huge power draw. Lights are pretty big draw. I don't know about the wrecker type winches. I drove a rusty '87 Dodge with mason's dump and plow - gummeymint work truck that got little love - and IIRC power connections for them were at the battery. The two radio - I don't know where it was tied in. Didn't matter. It was only turned on when the truck was running. Only point is that truck survived 15 years, and there was a near identical one a nearby town owned. Same age, more rust, different color - maybe no 2 way radio. LOL.

It also sounds, from all the reading I've been doing, like it's not a bad idea to put in a higher output alternator. The one on it is stock. Even with crackedback's headlight relay added on, the headlights dim at idle.
Well this becomes a difficult subject.
Sniper has posted that his all original car does not dim its headlights.
I don't know if its the lamps on the car draw less, the wiring is in better shape, or the alternator is an original with matching rotor and stator.
But many folks do see that, and not surprising, the ammeter showing slight discharge - especially with turn signals on and foot on the brake (stop lights on).

All alternators produce less power at low rpms.
Many 'rebuilt' and 'remanufactured' alternators no longer have the original stator and rotor - so they may be a mismatched set. They work, but prob not as efficient, which shows up most at low rpm.
Some 'high output' alternators produce more power at low rpms than stock, and many do not.
I think sometimes we shoot ourselves in the foot because the 'high output' alternator was made by installing a rotor that has higher current draw. So sure it produces a stronger electomagnetic field, but it sucks more juice to do so. So depending on idle speed, it may use more current than it produces. Also if the regulator can't handle the higher current draw, it will fail sooner.

My only suggestion is to shop carefully to be sure you get one that has better output at idle than the one you already own.
I *think* some of the high output alternators Chrysler installed were a different design and manufacture. For example there's some 60's service bulletins in Hamtramck-Historical showing a Leece-neville alternator which used had wiring to the regulator similar to shown in the '73 optional diagrams.
Posted By: larrymopar360

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/23/19 04:10 PM

If you decide to go NOS gauges, here's a good price on O/P. NOT mine.

https://www.ebay.com/itm/72-77-dodge-pick-up-truck-nos-oil-pressure-gauge-3635176/264508064991?
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/24/19 03:43 AM

Quote

I have a FSM for the truck


Ran across this.
https://web.archive.org/web/20180711165857/http://dave78chieftain.com/Ignition_Syste.html
At the bottom is a nicely done diagram of '73 and '74 wiring.
The original pages still exist but the archived version's images are easier to see thanks to P-Bucket mad
http://dave78chieftain.com/Ignition_Syste.html
It shows that motorhomes in '74 got a remote shunt ammeter, and the main feeds from the alternator and the battery join in the engine compartment. Then the power through the firewall is split, one wire going to the key switch, the other to the circuits that are always hot.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/25/19 12:10 AM

Thanks for finding that. My FSM shows the full blown system, with no separate diagrams really, for each area of the vehicle. Makes it a little harder to work through, to me. I bought a blown-up version, with some color coding to it, from Classic Car Wiring.

Won't be able to get into this till after the weekend. Who is a good vendor for things like the FL wire, good crimp connectors and a good set of crimpers? Still have cleanup on the dash and gauge cluster to do, testing the oil, temp, and fuel gauges, and repainting the needles
Posted By: RapidRobert

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/25/19 01:11 AM

Somebody suggested that Marine quality items/wiring are the way to go along with good crimping/soldering/shrink wrap tubing
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/25/19 03:56 AM

Originally Posted by jcruse64
Thanks for finding that. My FSM shows the full blown system, with no separate diagrams really, for each area of the vehicle. Makes it a little harder to work through, to me. I bought a blown-up version, with some color coding to it, from Classic Car Wiring.

Won't be able to get into this till after the weekend. Who is a good vendor for things like the FL wire, good crimp connectors and a good set of crimpers? Still have cleanup on the dash and gauge cluster to do, testing the oil, temp, and fuel gauges, and repainting the needles


Those diagrams I posted are created using the factory diagrams. Rarely did they provide schematics and even rarer were harness layouts in the FSMs.
It's up to us (the Techs) to use the factory diagram to make what we need.
http://www.imperialclub.com/Repair/Lit/Master/247/index.htm

I do about half on paper but easiest to post up the ones I've done the computer using MS Paint and IRFAN.

I'm one of those who likes marine grade wire. Can usually walk in and buy by the foot - if there's a marine supply in the area. Most parts stores carry automotive wire with GP (General Purpose) insulation. It's OK. But for high heat or locations where they may get covered in oil, there are better grades for that purpose.
Crimpers - Well a couple years ago I went full into using factory type connectors. Packard 58 and Packard 56 which use 'open barrel' crimps on the wire and another on the insulation.
For the most the Astro crimper with changable jaws has been pretty good. For some of the male terminals the jaw is too wide. I know a couple people who have ground the jaws. I ended up buying yet another crimper from American Wire (a copy of the Packard electric crimpers).
For heavier loads, ring terminals are good or connector that has more contact area than the Packard 58/56.

For factory wires colors may have to go to a place like Rhode Island Wire. Fusible link is pretty readily available. For links with Chrysler colors I've seen some places selling those, just can't recall who off hand.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/25/19 12:46 PM

Nice work on those diagrams, and thanks for posting them out there!
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/27/19 09:21 PM

Looking through both the FSM and the Classic Car Wiring diagrams, the welded splice off the alternator feed is made on the cab side of the bulkhead connector. On the DodgeCharger.com forum thread, it looks like user PocketThunder's Charger is the same way; the welded splice is on the inside of the vehicle. If I'm reading his posts correctly, he cut and capped the original alternator feed wire on the engine side of the firewall, where it would have gone INTO the bulkhead connector. He also capped off the other side of the original feed inside the car under the dash where come OFF the bulkhead connector. He left the other end of this wire ON the amp gauge where it was always connected. Along with it is his new Alternator wire to the amp gauge, both of those on the same post. If I see this correctly, in this way, he has power to his key switch, light switch, and fuse box, because the new alternator wire is now connected to whats left of the old alternator wire on the "black wire" post of the amp gauge. Am I seeing that correctly? Is that a good idea if the original alternator wire bulkhead connectors are not safe to leave in place?

On your diagrams, Mattax, I'm guessing that the FL on the alternator side that I see there are for instances when something screws up with the alternator, such as with the "fried harness wires. Why??" thead??
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/28/19 12:53 AM

Originally Posted by jcruse64
Looking through both the FSM and the Classic Car Wiring diagrams, the welded splice off the alternator feed is made on the cab side of the bulkhead connector. On the DodgeCharger.com forum thread, it looks like user PocketThunder's Charger is the same way; the welded splice is on the inside of the vehicle.


Yes. That's the norm on the older cars. A welded splice inside that acts as the power distribution point.
I just wanted to be sure that's what your truck had.

Quote
If I'm reading his posts correctly, he cut and capped the original alternator feed wire on the engine side of the firewall, where it would have gone INTO the bulkhead connector. He also capped off the other side of the original feed inside the car under the dash where come OFF the bulkhead connector. He left the other end of this wire ON the amp gauge where it was always connected. Along with it is his new Alternator wire to the amp gauge, both of those on the same post. If I see this correctly, in this way, he has power to his key switch, light switch, and fuse box, because the new alternator wire is now connected to whats left of the old alternator wire on the "black wire" post of the amp gauge. Am I seeing that correctly? Is that a good idea if the original alternator wire bulkhead connectors are not safe to leave in place?


I think you are interpreting it correctly.
I don't see any particular advantage or disadvantage to leaving the original alternator output wire vs. removing it. And if it is removed, I think leaving the original segment to the connector is pretty safe. But if you wanted to remove it and tape it, you could do that too. I'd wrap it up against the harness so it didn't flop around.

[img]http://www.dodgecharger.com/forum/index.php?PHPSESSID=feg5ibvs5qqmhsv7qgkli8n8c2&action=dlattach;topic=33574.0;attach=264330;image[/img]
Quote
On your diagrams, Mattax, I'm guessing that the FL on the alternator side that I see there are for instances when something screws up with the alternator, such as with the "fried harness wires. Why??" thead??


Which diagram are you looking at? The optional wiring ones earlier in thead?

And yes, alternator internally grounding failure occassionally happens. Also sometime a wrench touches the exposed alternator batt terminal while the battery is hooked up. Actually should be a insulating partial cover over it - but many cars no longer have them.

Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/28/19 01:16 AM

If the output terminal gets loose, or the insulating washers fail, then the battery can short to the housings.
Same if any part of the positive rectifier touches ground.
Some of theguys who know more about electronic tech may be able to say whether diode can fail in way that would let through high current (in the wrong direction). I pretty sure they sometimes can slowly 'leak' in reverse when they fail.

Attached picture Squareback-rectifier-inside.jpg
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/28/19 01:24 AM

"Which diagram are you looking at? The optional wiring ones earlier in thread?" Yes, those are the ones. I'll take the firewall plug apart and look the alternator feed connections over this week. If they are in good shape, I'll give as good a cleaning as possible, pack it with dielectric grease, re-connect, and leave it in use, along with a new wire on that side coming in through a grommet. Will be replacing the red wire.

Can't wait to get the dash back together and see how it looks with the new LED's.

Again, thanks, to all, for the time and knowledge/experience. As I get this back together, I will try to post how I did it, with pics, and how well it does.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/28/19 01:32 AM

OK. Lets see if this works.

On the A-body version, there's just one fusible link. It can protects all the wiring downstream that is 16 gage or larger. In other words, it should melt before the 10, 12, and even the 14 gage wires on the ignition circuit.
[Linked Image]


On the B-body version, the green 10 gage fusible link should melt before the 6 or 8 gage wires leading to the alternator.
A blue 16 gage FL protects the standard 10, 12, and 14 gage wires.
[Linked Image]
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/28/19 02:10 AM

A couple of follow up observations.
With the 65 amp B-body wiring, it becomes tricky to run parallel wires from the alternator to the main splice. If we run a FL on each, then we main not be adaquitely be protecting the smaller wires.

16 ga FL ---10 ga ----12 ga----Welded---12 ga---Fusebox
16 ga FL ---10 ga ----12 ga----Junction---12 ga ---switch ---14 ga ----

Now lets say that 14 ga wire rubs on some metal and ground out.
Power from the battery can flow through both fusible links. Sure it will take the shortest route first, but as resistance increases, it will find the next easiest path.


I noticed the Q3 label on my diagram didn't make sense (accessories are switched)so I went back to the service manual to see what it should be - fusebox. Duh!

While looking at the FSM, I noticed there was also a 60 amp wiring option for the b-bodies with a more practical wire sizes to work with.\
Be interesting to see whether it ends up more like the A-body 60 amp or B-body 65 amp wiring.
It looks like the 65 amp was a special leece neville unit. Someone may know more about that.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/28/19 02:26 AM

Thank you. I'll study some more on my FSM diagram tomorrow. Thanks for telling me how those wire code designations work; starting to make more sense to me now. I thought a route code of some type for each wire length.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/28/19 03:42 AM

FWIW the 60 amp B-body option has same layout or concept as the 65 amp option.
But it only uses one extra terminal and has smaller, more reasonably sized wires and links.
Here's the quickest version I could do.

Attached picture 1973-60Amp-Charger-Cornet-temp.png
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/28/19 05:51 PM

If I DID end up replacing the alternator, and went up to an 80 or 85 amp version, will the 10 gauge wire still be fine? I've no need for anything bigger on alternators in this rig.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/29/19 01:39 AM

This is what Nacho was talking about. It doesn't really matter what the maximum the alternator is capable of.
When sizing wires the question is how much power the lights or equipment will draw?
Then the fuse is selected to never open under normal current draw, but to melt well before the smallest wire would melt if grounded.

The other thing about the alternator is that it will stop producing power if there is short to ground in the system. If current is shorting to ground, its no longer flowing to the rotor and so the magnetic field collapses. Result is no power.

Lets look at the 60 amp Dart wiring. It originally showed that with extra equipment on the alternator side of the ammeter. IIRC its the rear window electric defroster. So that can draw a bunch of current. Therefore its probable the optional wiring arrangement was designed to support that extra current. Notice they left the standard 16 gage fusible link.

The battery recharging is the only device that is difficult to plan for. At least I think so.
The amount of current it will draw depends on how much its depleted as well as the supply current.
On the stock alternators, the alternator power at idle was a limiting factor which helped keep the battery from charging too rapidly.
Now IF this new 85 amp alternator can produce 45 amps at 14 Volts while idling, and the battery is low, this is when the larger wires will stay cooler.
5 amps will go to running the ignition and supplying the field, and the other 40 amps will go to the battery for recharging.
As the battery gets recharged, it will draw less and less current even when supplied with power at 14 Volts.

But if the engine is running and the battery is only being used for starting (and maybe to help a little at stop lights with lights, wipers, A/C) then I would think you could stay with the 16 gage fusible link in he battery feed. As a 16 gage FL would protect the system as well as stock, then a second one coming off the terminal block would not be needed.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 10/29/19 11:46 AM

Mattax, I'm leaning towards taking it all out of the bulkhead connectors. In your last diagram, any reason I can't come on from the 12 gauge wire on the cab side, where the splice goes to the ignition, lights, and fuse box, and splice in a length of additional 12 gauge black wire through the grommet at the firewall, to the engine bay? Your diagram has the 8 gauge from the alt hitting a terminal stud, where 10 gauge goes to a 16 gauge FL, to 10 gauge, to the bulkhead connector, to that 12 gauge on the cab side. Can I just carry 12 gauge through the grommet, straight into the 16 gauge FL? Can the 14 gauge FL connect straight to that terminal stud? or is there a reason 10 gauge wire comes off it, and then into the FL?

I'm planning on doing this per that last diagram, as it matches very well with the truck's setup. I'm going to unwrap all the loom needed to get the original wires being eliminated OUT of the loom, and re-wrap new wires in where positioned, with the cloth loom tape and/or the split loom sleeving. Got everything ordered but the actual connectors.

Thanks!
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/01/19 03:51 PM

Mattax, this is what I was thinking of. I have the harness unwrapped under the dash to get the wire from the welded splice to the amp gauge cut and taped off, and the wire from the cab side of bulkhead to where I can splice new 12 gauge bl wire from where I cut off the bulkhead connector. Feed that newly spliced 12 gauge bl wire through the same new firewall grommet as the 2 new amp gauge wires. Run it to the new 16 gauge FL, which goes to the terminal block on the alternator feed line.

Meant to ask; what can I use to remove the connectors in the bulkhead blocks? I want to remove both black and red wire completely from the bulkhead blocks.

Thanks,

Joe

Attached picture 1973-60Amp-Charger-Cornet-temp.png
Posted By: moparx

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/01/19 04:12 PM

if you don't have dedicated removal tools, a tiny eyeglass flat screwdriver will work. [those sets can be found almost anywhere if you don't have any, and they are cheap]
on the female terminal, shove the screwdriver into the slot above the top of the terminal, flattening the tiny tab that holds it in.
on the male terminal, you will take the screwdriver and shove it inwards along one side that will push the one leg inward, releasing it from the bulkhead.
it may take some fiddling around to make this work, but patience is king. if you are not sure what i'm refering to, look up "packard 56" terminals. that will show the tab on the female, and the leg on the male.
hope this helps.
beer
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/01/19 05:56 PM

Thanks, and I really appreciate the help in sorting the wiring diagrams out. I'll report back in this thread on how this goes (and hopefully not the charred remains of my truck, lol).
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 01:00 AM

Sorry I've been busy.

I do think that what your showing - going through a grommet with the power feed - is more robust.
If you don't want a fusible link in that line, then just use a 16 gage one in the line to the battery.

Personally I try to leave the welded splice alone.
I would look at taking the two R6 wires and joining them, maybe at a good connector.
Or if that doesn't look like it can be done well, clip one long and tape it to the other. That would be neater and not risk having stub that could poke through the tape. Maybe gently tie wrap it for good measure.
But do what you are comfortable with and makes sense when your're looking at it.

Moparx mentioned the tools and the connectors.
A lot of Chrysler terminals are a little different than Packard 56. I believe they are Packard 58. The male 56 and 58 terminals may be the same. But not only do the 58s look different, they also have slightly different length - so do not always work in the same plastic connector.

I started a thread about them on FABO.
https://www.forabodiesonly.com/mopar/threads/sources-for-chrysler-type-wire-terminals.418908/
Can't recall if we discussed them here (moparts) in any threads but might have.

For your new power feed, might see what else is available that would provide good contact area and positive locking.






Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 02:53 AM

No, I like the idea of having the 16 gauge FL on the wire that goes to the welded splice under the dash; I think you're right and that it will help prevent a massacre if the alternator shorts or something else screws up on the alternator side.

I'm not going to mess with the welded splice. I'm thinking that I'll cut the packard terminal off the R6 that comes out of the bulkhead inside the cab, put 12 gauge BL wire to that wire end with an insulated connector, and go out to the engine bay through the new grommet and terminate at the terminal block, where it meets the 8 gauge black wire from the alt, and the 10 gauge wire going to the amp gauge. Would a butt connector be appropriate here? The black R6 that currently goes from the welded splice to the amp gauge, I'll remove from the amp gauge, and tape off/insulate, per your last diagram.

By the way, what kind of connector is that referenced on the FL's in the diagram? I'd rather use something other than a butt connector with FL's; easier to replace the FL if something burns it out. The factory FL at my starter relay has a connector that allows easy disconnection.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 01:24 PM

I don't know. Google search for Moapr fusible links turns up some images.
Looks like ones used on these
[Linked Image]
https://www.hiltopautoparts.com/pro...-4-c-body-battery-cable-to-main-harness/

Earlier cars like mine use this one.
[Linked Image]
from this page
https://www.yearone.com/Catalog/chrysler.b.body/electrical/fusible-links

Maybe someone here will know. Otherwise its hunting through catalogs.

This guy's page is has a bunch of links.
http://www.rowand.net/Shop/Tech/AutomotiveElectricalConnectors.htm
Posted By: moparx

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 03:00 PM

sorry if i caused confusion on the connector types.
as usual, i just ASSumed they were the same as earlier stuff. spank
there are just SO many types of connectors used these days, i have a whole drawer full of different removal tools, but i'm constantly buying more because i don't have what i need for the job at hand.
beer
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 03:19 PM

Nothing to apologize for IMO.
I thought they were all Packard 56 - that's what I saw posted on jeep forums, here, Forabodiesonly etc.
Someone mentioned there were different types, but only when I was working on my '67's harness did I see that most (all?) of the '67 harness female terminals had the rolled edges for spring tension. Then when I replaced a terminal on the M&H repop engine harness, I found out for myself the Chrysler type (Packard 58 style) didn't stay in the connector housing for the Packard 56. confused Then I compared the terminals and fortunately I had saved the original harness. So I was able to use the original plastic terminal cover and all was well.

Chrysler also used 'twin locks' (steering column wiring connectors) and others which I don't know the names of.

PS. Slightly off topic, but related to the project. Inside the firewall connectors, there is a foam seal on the half with the male terminals. Detroit Muscle Technologies makes those. For the truck might have to contact Jim to see what he has or can make.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 04:49 PM

Here is the stock connector on the FL to the starter relay on this truck. That's a Packard terminal inside the plastic housing, isn't it? What kind of housing is that? Can I remove those housings and reuse? I didn't want to mess with it for fear of breaking them.

Attached picture FL Connector.JPG
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 05:23 PM

It's getting even better, lol. The PO had "wired in" a few things, over the years. Extra in-cab light over front seat off of a line on the light switch harness. He ran the power for the wench on his wrecker boom by coming off the starter relay to a second relay for power, and running a wire to the second relay. While unwrapping more of the harness in the cab today, and chasing down the wires I cut from his emergency lights and flashers for the wrecker boom, I found how he powered them. Off the power wire to the ignition, it appears. This has been hot enough that I don't think I can get them apart without destroying the plastic connector. I think this needs replacing. Looks like RockAuto might have it

https://www.rockauto.com/en/moreinfo.php?pk=944615&cc=1100552&jsn=1006

Anyone have another source for this ignition switch harness?

Attached picture Ign-1.JPG
Attached picture Ign-2.JPG
Posted By: Sniper

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 05:51 PM

Standard Motors SU88
Napa Echlin KS6611

If you are looking for the other end of that connection, sorry no info.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 06:22 PM

If both sides are bad enough, I can always run single-connection housings. I found a source for those. I'm afraid both sides have "meltage".
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/02/19 10:26 PM

Clips and fasterners is calling itone way Metripack and 56. ????
You may be able to follow the links and get to Auveco catalog page.
https://www.clipsandfasteners.com/O-E-M-Terminals-Shells-s/259.htm


Delphi is what used to be Packard Electric. You can take the Delphi p/n and see what a web search engine turns up.

Ignition - column connector looks very similar or the same as used in a-bodies of that era. Might have some luck finding that.
Or more likely a general multiterminal connector for the larger size and seperate one for the smaller size.
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/03/19 12:20 PM

Damn! I have being lazy to read all this thread with detail, but fortunatelly Mattax is around!

About the ign switch and harness. Sorry, those SPECIFIC conectors are not available unless NOS ( althought repro harnesses must get those for somewhere we don't know ). Female end is included with ign switch thought. Terminals itself are Standard Molex ( Molex is the designer/manufacturer of those terminals ) and they are available in two sizes. Generic conectors are available in several setups, 1, 2, 3, 4, 9, 12 ways, some of them for both sizes. Some of them were used in Mopar harnesses but NOT the ignition switch ( not at least on the shops I have searched ) since they are specific for those using 3 cavities for the small size and 5 cavities on the bigger size.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/03/19 01:43 PM

Main culprit is the big black power wire. Probably NOT just because the PO had hacked into it on both sides. On a RC/truck forum I'm on, a few have told me that it was pretty common for this exact thing to happen within a few years of production. Some went ahead and cut the black wire out of the harness and just spliced it together. I'm thinking that finding a better way than that connector is the better way to go, even if it means running all wires to their own, individual terminal blocks.

First things first, though; when the wire and supplies get here, I'll get this alternator feed diagram into reality, and get the dash back together and in place.

Thank,

Joe
Posted By: krautrock

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/03/19 03:42 PM

just did this on my 77 w200 yesterday.
there has been an aftermarket ammeter in the truck since i got it. i drove it all morning yesterday running errands and i smelled some hot plastic, also noticed the ammeter was showing about 40amps charge when the rpm's were high enough for the alternator to put that out.
i had previously pulled the bulkhead connectors off and sprayed some deoxit in there and worked the connectors in there a few times in hopes of buying some more time.

thought about what i was going to do, decided to pull that connector where the black wire from the alternator goes into the bulkhead, it was melted pretty good. i ended up taking a larger wire from the alt output to the batt+ on the relay, also ran a 10g wire from that same post and went through a hole in the firewall right below the bulkheads. i cut the wire back where it feeds to the wiring harness for power and to the ammeter inside the cab, some of it was burned and corroded. just used a butt connector to attach my 10g wire to the original black 10g wire. so bypassed the bulkhead where it melted.
i thought i had a voltmeter hanging around to replace the ammeter but didn't so just left the ammeter. it's not accurate now but i don't really care. just needed to get the truck running again.

i think at this point i might as well put one of the denso alternators on it and put a voltmeter in it....
Posted By: RapidRobert

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/03/19 05:53 PM

Quote
also noticed the ammeter was showing about 40amps charge when the rpm's were high enough for the alternator to put that out.
dont drive it anymore till you solve it cuz that high of rate will fry everything (I'm assuming the battery is charged & if it ain't then charge it with a charger on your bench).
Posted By: moparx

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/03/19 06:00 PM

if you need, or want, any of the ganged, standard molex connectors and terminals, let me know.
i have a good supply, and you can have what you need, gratis.
i have more than i'll need for the rest of my days, and someone might as well use 'em up.

also, i have repaired MANY of those in the past, and they ARE commonly "melty".
beer
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/03/19 07:15 PM

Originally Posted by moparx
if you need, or want, any of the ganged, standard molex connectors and terminals, let me know.
i have a good supply, and you can have what you need, gratis.
i have more than i'll need for the rest of my days, and someone might as well use 'em up.

also, i have repaired MANY of those in the past, and they ARE commonly "melty".
beer


Sending PM. Thanks!!!!

Joe
Posted By: krautrock

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/03/19 07:40 PM

Originally Posted by RapidRobert
Quote
also noticed the ammeter was showing about 40amps charge when the rpm's were high enough for the alternator to put that out.
dont drive it anymore till you solve it cuz that high of rate will fry everything (I'm assuming the battery is charged & if it ain't then charge it with a charger on your bench).


well after i rewired the alternator output to the b+ post on the starter relay and then ran the new wire to the ammeter, the ammeter shows almost no activity.
voltage at the battery at low idle (didn't let the motor warm up much) was 12.8V and if i revved it, 13.3v. no wires were hot all so i imagine it's fine now.

yeah with the bad connection in the ammeter wire at the firewall, it was about 10amps at idle and if i revved it was about 40amp, the needle was also jumping around at idle...the wire was warm to the touch after i started looking around, could also smell it...
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/03/19 08:18 PM

Originally Posted by RapidRobert
Quote
also noticed the ammeter was showing about 40amps charge when the rpm's were high enough for the alternator to put that out.
dont drive it anymore till you solve it cuz that high of rate will fry everything (I'm assuming the battery is charged & if it ain't then charge it with a charger on your bench).



time to wonder HOW MUCH ACCESORIES HAS BEING SOURCED FROM BATT POST ? WRONG PROCEDURE...ammeter cars must get accesories sourced from alt post or some buss between alt and amm. If not any charge reading won be necesarily on charging batt process but feeding those added accesories. Then you wonder why ammeter and installation burnt!!!!

any excesive charge or discharge reading is an alarm. If nobody pays attention OR THINK a Charge reading is NORMAL you don't know how to read an ammeter or how the system works. Don't blame the ammeter cause that! Ammeter is giving you a warning call either side of the reading. Pay attention!
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/04/19 03:08 AM

krautrock,
If the alternator output goes to the battery directly, then the ammeter is no longer being used.
For an ammeter to work it need to either be directly in the battery charge wire, or in parallel to the battery charge.
If the meter is in parallel, its an externally shunted ammeter. Chrysler was using external shunted ammeters in a-bodies by '76. Earlier in some of the other car lines. Trucks I don't know.

Whichever type ogf ammeter was added, the question is why was 40 amps going to the battery?
Or was there anything else hooked to the battery?

This is the one disadvantage of having a voltmeter but no ammeter. The Voltmeter can only indicate whether the regulator and alternator are working. It can not show whether how much charging or discharging is occuring.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/04/19 03:41 AM

This is a slightly cleaned up version of the '74 Motorhome diagram made by Dave78chieftan (linked earlier in this thread)

It shows an ammeter with remote shunt. The shunt is the wire marked A20A - 10 Black
From each end of that shunt wire, 18 gage wires go to the ammeter.
(What he called a 'main' junction is not the same as the main splice we normally discuss where battery and alternator power wires join with the distribution wires.. His is just a junction on the run circuit.

Attached picture 74-Motorhome-Dave78Chieftan.png
Posted By: krautrock

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/04/19 02:48 PM

Originally Posted by Mattax
This is a slightly cleaned up version of the '74 Motorhome diagram made by Dave78chieftan (linked earlier in this thread)

It shows an ammeter with remove shunt. The shunt is the wire marked A20A - 10 Black
From each end of that shunt wire, 18 gage wires go to the ammeter.
(What he called a 'main' junction is not the same as the main splice we normally discuss where battery and alternator power wires join with the distribution wires.. His is just a junction on the run circuit.


thanks for posting this diagram. looked at a wiring schematic just now.
seems i need to modify my wiring some.
right now the alt output goes to the b+ on the relay, then i have a 10g wire that goes from the b+ to the A20A-10BK inside the cab, there is a splice somewhere in there that goes to the headlights and something else, then it goes to the ammeter. Then, the other side of the ammeter is original so it is the same as the S1-10-RE in the diagram, so it goes back to the B+ on the starter relay. both connections being at the B+ on the starter relay is going to cause it to be inaccurate right?

I started my truck this morning to have a look at the gauge once again, the starter makes the gauge show 15a discharge, then at a slightly high idle it shows about zero, if i rev it up some, it shows a few amps on the charge side.
Like i said before, at a low idle, voltage at the battery was about 12.8v and if I revved it up some it was about 13.3v.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/04/19 05:29 PM

Originally Posted by krautrock

thanks for posting this diagram. looked at a wiring schematic just now.
seems i need to modify my wiring some.
right now the alt output goes to the b+ on the relay, then i have a 10g wire that goes from the b+ to the A20A-10BK inside the cab, there is a splice somewhere in there that goes to the headlights and something else, then it goes to the ammeter. Then, the other side of the ammeter is original so it is the same as the S1-10-RE in the diagram, so it goes back to the B+ on the starter relay. both connections being at the B+ on the starter relay is going to cause it to be inaccurate right?

I started my truck this morning to have a look at the gauge once again, the starter makes the gauge show 15a discharge, then at a slightly high idle it shows about zero, if i rev it up some, it shows a few amps on the charge side.
Like i said before, at a low idle, voltage at the battery was about 12.8v and if I revved it up some it was about 13.3v.


It sounds like your truck's ammeter has an internal shunt.
Because it sounds like it originally had a heavy wire from the fusible link all the way to the ammeter, and a heavy wire from alternator output to a splice or splices with a brank to the other side of the ammeter.
A remote shunt would have small 18 or 20 gage wires going to the meter.

Using that diagram is probably not the best if the rig had an internally shunted ammeter.
From what you've described maybe something like the first one below.
The second one is typical '73 car. I dont have truck diagrams so can't help with that. That motorhome one the guy drew is the only thing I've seen.

15 amps discharge while starting is huge.
The question is why is any current going through the ammeter when you have it wired this way.
As far as the voltage goes, its not very informative. Could be anything from blown diodes to a short sucking power from the alternator.
I think you're best off wiring it up like the factory (using new connectorsand a grommet instead of going through the melted ones).
Then hunt for shorts with battery discnnected, or live, using a circuit breaker where the fusible link(s) goes.


Attached picture KR-WIP.png
Attached picture Charging-diagram73.png
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/04/19 05:30 PM

I have reading a bit more this thread. So far so good I can say:

@jcruse64 you don't need to remove the existant wires from bulkhead if they are in good conditions! You can help them with a parallel wiring. That's why I meant a parallel wiring toward to reinforce the existant one. If they were burnt and you were not interested on reinforce it, well remove could be ONE way to make it. HOWEVER I like the idea about keeping it, why?:

Ok, note the diagram! On a standard setup the main splice on cab side gets tipically a 12 wire running to bulhead and one wire running to ammeter. When you install a paralel wire, the stock wire will be still feeding the splice from alt wire, and the parallel will feed the splice from the ammeter side wiring. So your are feeding the splice on two 12 wires ( no matter the gauge of the wire of the parallel path, just talking about both wires arriving to splice )

If you remove the wire from bulkhead you are limiting the splice to be feeded from just one 12 wire, the one coming from the ammeter side. The only way to make this better is feed the splice straight from the parallel path, and replace the wire between amm and splice with a similar one, instead make it easy just using the amm stud as a juntion and keeping the stock one. This becomes on a deeper modification, going straight to the splice. Is not hard, but reach that?

The extra thickness on the parallel path will help on a more efficient charging process when needed supplying the load to the batt throught the amm if was required.

Next... wiring must be matched to the nominal load the car will be sucking as a constant and able to support some peaks INCLUDING the batt load recharging process. IMHO THIS WAS NEVER CONSIDERED by Chrysler same as the real alternator capacity required to a balanced electrical system.

You were asking about what's the wiring gauge required for the upgrade? Keeping the stock 12 gauge one 10 gauge is more than enough. I used 8 on my car for the parallel path just because I had that wire on hands, but could use very well 10. Use 8 won't hurt anyway.
Posted By: krautrock

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/04/19 06:03 PM

Originally Posted by Mattax

It sounds like your truck's ammeter has an internal shunt.
Because it sounds like it originally had a heavy wire from the fusible link all the way to the ammeter, and a heavy wire from alternator output to a splice or splices with a brank to the other side of the ammeter.
A remote shunt would have small 18 or 20 gage wires going to the meter.

Using that diagram is probably not the best if the rig had an internally shunted ammeter.
From what you've described maybe something like the first one below.
The second one is typical '73 car. I dont have truck diagrams so can't help with that. That motorhome one the guy drew is the only thing I've seen.

15 amps discharge while starting is huge.
The question is why is any current going through the ammeter when you have it wired this way.
As far as the voltage goes, its not very informative. Could be anything from blown diodes to a short sucking power from the alternator.
I think you're best off wiring it up like the factory (using new connectorsand a grommet instead of going through the melted ones).
Then hunt for shorts with battery discnnected, or live, using a circuit breaker where the fusible link(s) goes.


my truck is wired like this now.
[img]https://board.moparts.org/ubbthreads/ubbthreads.php/ubb/download/Number/377296/filename/KR-WIP.png[img]

wired this way, is the ammeter going to be accurate?
Posted By: krautrock

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/04/19 06:40 PM

here are the images i've used before, yellow points out the ammeter wiring...hope this helps people out...

EDIT: this is for a '79 model truck

Attached picture 79_Dodge_Truck_Wiring_Diagram ammeter pages_Page_1.jpg
Attached picture 79_Dodge_Truck_Wiring_Diagram ammeter pages_Page_2.jpg
Attached picture 79_Dodge_Truck_Wiring_Diagram ammeter pages_Page_3.jpg
Attached picture 79_Dodge_Truck_Wiring_Diagram ammeter pages_Page_4.jpg
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/04/19 08:57 PM

Nacho, thank you for the feedback.

My bulkhead is not great, but it's not as crispy as my ignition harness coming out of the column.The plastic is on the brittle side though, and that worries me. Is there a disadvantage to separating feed to amp gauge OFF of the stock path to the welded splice inside the cab?? Will keeping the feed from alternator to amp gauge on separate path, after the terminal stud in the engine bay, affect correct readings of the amp gauge?

I've even considered cutting out the welded splice in the cab, running the new feed wire from the alternator into a buss under the dash, and then running separate black wires each to the ignition, fuse block, and headlight switch. I could also run the black wire to the amp gauge off this buss. This would be pretty much the same as the stock, welded splice, would it not?

Again, I thank ALL of you for your feedback! As I pull tape off looms, and inspect the unwrapped tape, especially under the dash, I see more wire that has either been cut into by the PO, roughed up by decades of road time, or chew marks by rodents. I will be picking up more spools of correct gauge/color wire soon, with correct connectors, and replacing these. The fuel gauge line and the line from fuse box to bed light switch are 2 good examples of needing replacement. I've aready had to do a hack job of soldering on the orange wire under the dash, where there is a factory welded splice, to repair rodent damage. This, too, will be getting attention, now that the dash is all out.

I need to read up more on building relays into the harness. I'd like to put my heater fan switch on them; at least the High setting.

This is a good learning experience for me. At some point, this truck will be Daily Driver status; soon, I hope. I have a '76 Ramcharger to get into next, and the wiring is bad enough on it that I'm going in with a new wiring harness from someone like Ron Francis or Painless.
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/04/19 11:05 PM

I'm travelling right now and can't post as much I'd like due the poor connection. Was trying to post this since couple of hours LOL. Later will get deep into some sugestions.

I'm noticing also you are talking about the shunted system! Need to say the shunted system is different from the full load ammeters. Shunted system or wiring is a remote ammeter reading using miliamperes running throught the 16 gauge wires. You won't get same results wiring a full load system like a shunted systems. Ammeters with shunted systems gets a mounted on coil to amplify the needle movement with just miliamperes thanks to the resistance the shunt provides.

Attached an ammeter to shunted systems, used on Mopars since 75/76 so be careful what diagram you use as a guide!

Ammeter for shunted wiring
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/05/19 01:14 AM

The '79 truck diagrams Krautrock posted show it is a typical basic power supply strategy with just a few modifications.
It has internal shunted ammeter - power flows directly through it, not in parallel.
That clears up what Krautrock and probably the OP are dealing with. Thatnks Krautrock!

The power is distributed at the main splice, with two exceptions which we'll come back to later.
When the alternator when its producing power at higher voltage than the battery, it flows through the bulkhead connector to the main splice.
When the battery voltage is higher, power flows from the battery to the main splice by going to the starter relay, through the fusible link, and then through the bulkhead connector, and the ammeter.

This schematic based on a '73 Dart shows the two paths to the main distribution point.
[Linked Image]

On the '79 truck diagram, that distribution point is the highlighted splice below the headlight switch.
A20A from the bulkhead to the splice is the path current flows from the alternator to where ever it is needed.
A20A from the ammeter to the splice is the final leg of the path current flows from the battery to where ever it is needed, when the alternator can't supply it.
All of the other wires are branches to supply power to different locations. Notice on this truck there are two power supply wires to the ignition switch.


Attached picture 1979-truck-p45connect.png
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/05/19 01:36 AM

In the previous post, I highlighted wire F38, purple with white stripe. That's one of the two exceptions to distributing power at the main splice.
It comes from the battery positive through a fusible link and the bulkhead connector.
Its power for the 4-way /hazzard flashers. The designers mayt have decided the flashers would generally run when the engine was off, so they conencted them straight to the battery.

The other exception is the DS1 10 gage red wire. I don't know what that is for. Maybe to the horn relay??

One thing that is very different on this truck is the starter relay itself.
I'm not familiar with it. The orange wire seems to be the signal to trip the relay for starting.
The ignition start circuit gets power from the relay, as does of course the starter solenoid.
Just some things we'll have to keep in mind while trouble shooting.



Attached picture 1979-truckp23conn.png
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/05/19 02:46 AM

Originally Posted by krautrock
just did this on my 77 w200 yesterday.
there has been an aftermarket ammeter in the truck since i got it.

i drove it all morning yesterday running errands and i smelled some hot plastic, also noticed the ammeter was showing about 40amps charge when the rpm's were high enough for the alternator to put that out.


I agree with Rapid Robert on this.
Current climbing with rpms is a a battery with serious problems or some sort of short. Could be in the battery, or the wires crossing or grounding, or inside the starter relay?

Load test the battery and/or put it on a slow charge if its low.

Quote
thought about what i was going to do, decided to pull that connector where the black wire from the alternator goes into the bulkhead, it was melted pretty good.
i ended up taking a larger wire from the alt output to the batt+ on the relay,
also ran a 10g wire from that same post and went through a hole in the firewall right below the bulkheads. i cut the wire back where it feeds to the wiring harness for power and to the ammeter inside the cab, some of it was burned and corroded. just used a butt connector to attach my 10g wire to the original black 10g wire. so bypassed the bulkhead where it melted.
i thought i had a voltmeter hanging around to replace the ammeter but didn't so just left the ammeter. it's not accurate now but i don't really care. just needed to get the truck running again.

I understand now.
A voltemeter can not be used where an ammeter goes. Ammeters measure current running though them.
Voltmeter has very high internal resistance. It measures potential between two locations. No current flows through it.

Running the alternator output direct to the relay terminal might be useful if running a plow or winch off of the battery - and its a battery that can handle high charge rates.
One danger is no fusible link. If the alternator shorts internally - then the battery will send all the current it can down that new 10 gage wire - until it melts.
Anyway, to answer your other question, the ammeter is no longer accurate when there are two paths from the same point (starter relay) to the distribution point.

If the battery is good, then splice your alternator output to the A20 so the power flow is basically stock, but bypassing the bulkhead connector.
Then visually check over the battery feed/charge wire (S1 etc). While the battery is disconnected, use an ohmeter to see if there's connection to ground (shouldn't be, but that 40 amps indicates something is drawing current that shouldn't be)
Posted By: krautrock

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/05/19 03:56 PM

Originally Posted by Mattax

I agree with Rapid Robert on this.
Current climbing with rpms is a a battery with serious problems or some sort of short. Could be in the battery, or the wires crossing or grounding, or inside the starter relay?

Load test the battery and/or put it on a slow charge if its low.


I was thinking the bad connection at the bulkhead was making it show 40amps charge. Weird thing is, I was messing with the ammeter (an old aftermarket gauge) and at one point I started it back up and it showed zero charge for a bit...then all the sudden it started showing a high charge rate again...this was while I was troubleshooting connections and right before I realized how burned up the bulkhead connector for the ammeter feed was.

I drove the truck last night with it wired up the way I modified it. Huge difference in all the electrical stuff.
I think the situation slowly got really bad and I didn't notice.

1. Headlights are much brighter now and also, the turn signals blink much faster, even the instrument cluster and signal indicator lights are brighter. The headlights are not flickering at idle while in drive now.
2. The blower motor blows stronger
3. My brake lights and taillights are brighter as well.
4. I thought my wiper motor was going out again, on low they were acting like they were going to stop on the windshield at any moment, now they are working great.

I have an msd on the truck which has it's own power supply wire so the truck has always started fine.



Quote

I understand now.
A voltemeter can not be used where an ammeter goes. Ammeters measure current running though them.
Voltmeter has very high internal resistance. It measures potential between two locations. No current flows through it.

Running the alternator output direct to the relay terminal might be useful if running a plow or winch off of the battery - and its a battery that can handle high charge rates.
One danger is no fusible link. If the alternator shorts internally - then the battery will send all the current it can down that new 10 gage wire - until it melts.
Anyway, to answer your other question, the ammeter is no longer accurate when there are two paths from the same point (starter relay) to the distribution point.

If the battery is good, then splice your alternator output to the A20 so the power flow is basically stock, but bypassing the bulkhead connector.
Then visually check over the battery feed/charge wire (S1 etc). While the battery is disconnected, use an ohmeter to see if there's connection to ground (shouldn't be, but that 40 amps indicates something is drawing current that shouldn't be)


I'm going to have the battery load tested, I just looked and it's almost three years old, a Bosch 65-750BAGM.
I'm also going to do a quick check for shorts, I also think I might wire it up so the ammeter works correctly again but the bulkhead is bypassed and then see if it still shows a high charge rate. That might tell me if the burned up connection was causing that reading.

This truck has aftermarket gauges wired up so replacing the ammeter with a voltmeter would be pretty simple. Like I said, this stuff was all in it when I bought the thing 8 years ago, the gauges are so old some of the plastic inside is dry rotted and sitting in the bottom of the gauge sight window, I think it wouldn't hurt to put a new gauge in there, ammeter or voltmeter.
If I do the voltmeter and leave the alt output going to the relay, I would wire that up so that it has a fusible link inline with the alt feed. The two wires to the ammeter could just both bolt the + side of the voltmeter correct?
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/05/19 05:52 PM

I've got to run out now so will write more later.

Originally Posted by krautrock


I was thinking the bad connection at the bulkhead was making it show 40amps charge. Weird thing is, I was messing with the ammeter (an old aftermarket gauge) and at one point I started it back up and it showed zero charge for a bit...then all the sudden it started showing a high charge rate again...this was while I was troubleshooting connections and right before I realized how burned up the bulkhead connector for the ammeter feed was.

A high resistance connection on either alternator out or battery charge should reduce the charging.
(The ammeter could have a bad connection - but then it would be getting hot,and current would be reduced)
The terminal studs are pressed, welded or bolted to the shunt plate. If one or both are loose, then there will be a poor connection. Both should be insulated from the housing if it is metal.

One scenario is with high resistance in the circuit, the battery didn't get recharged time and time and again. When a good enough connection was finally made, the battery sucked all the current it could.
https://www.forabodiesonly.com/mopa...ternator-warning.424783/#post-1972341397

Quote

I'm going to have the battery load tested, I just looked and it's almost three years old, a Bosch 65-750BAGM.
I'm also going to do a quick check for shorts, I also think I might wire it up so the ammeter works correctly again but the bulkhead is bypassed and then see if it still shows a high charge rate. That might tell me if the burned up connection was causing that reading.

This truck has aftermarket gauges wired up so replacing the ammeter with a voltmeter would be pretty simple. Like I said, this stuff was all in it when I bought the thing 8 years ago, the gauges are so old some of the plastic inside is dry rotted and sitting in the bottom of the gauge sight window, I think it wouldn't hurt to put a new gauge in there, ammeter or voltmeter.
If I do the voltmeter and leave the alt output going to the relay, I would wire that up so that it has a fusible link inline with the alt feed. The two wires to the ammeter could just both bolt the + side of the voltmeter correct?


Fusible link or links should be placed to protect all wires downstream of the battery. The starter wires are the only exception.

You could tie the two ammeter leads to a voltmeter positive. Disadvantage is the voltmeter is on at all times.

Taking the alternator wires off the starter relay terminal will then let the ammeter only show power flowing to or from the battery.
It also means only one fusible link is needed on the main circuit.

This is what it would look like running except showing with Chrysler ECU.
Don't have time to redraw with MSD, but MSD main feed uses about 1 amps per 1000 rpm.

Attached picture 1979-truck-run-KRs.png
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/05/19 08:47 PM

Nacho, is this more in line with your thoughts. It looks similar to the "parallel" diagram you have posted on the Charger site, except that I left in a 16 gauge FL, and I took out the bulkhead feed, and made a straight shot to the welded splice. But it leaves the original black wire at the amp gauge in place, so that there are now 2 black wires on that post of the amp gauge.

Still unclear if amp gauge would be accurate if both black wires were not on the amp gauge post.

Joe

Attached picture 1973-60Amp-Charger-Cornet-Alternate.png

Description: Parallel route
Attached picture 1973-60Amp-Charger-Cornet.png
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/06/19 05:29 PM

Its parallel but has a 14 gage Fusible link protecting 12 gage wires.
Need to place a 16 gage Fusible link where the 14 gage link is.
Then the 12 gage wires are better protected. The current 16 gage link can be eliminated.

Yes the ammeter will work as normal. There's only one path to or from the battery - and that's through the ammeter.
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/06/19 05:38 PM

A parallel alternator output wire would be like shown below.

A second wire going to the same junction, or equivalent.
In this case its essentially equivalent because the only thing between the two is a wire.
It is a slightly shorte andr more direct route to the battery; so current for charging might prefer it over the route through the bulkhead connector and main splice.

Likewise, a parallel wire from the fusible link to the ammeter battery terminal could be added.

Attached picture Basic-Power-diagram6x-p.png
Attached picture Basic-Power-diagram6x-p-running-pll-.png
Posted By: krautrock

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/06/19 06:10 PM

^ i like the mod to just run a parallel wire to the ammeter from the alt output (and likely a parallel wire from ammeter to FL). if my bulkhead weren't so burned up already i think that would be a great simple way to save the bulkhead and keep the ammeter.

on another note, checking for shorts. quick and easy way is to just check for continuity from the circuit to ground with the neg battery terminal unhooked?
ie, I unhooked the neg battery, then, probed from the neg battery terminal to the b+ post on my starter relay, infinite resistance. safe to assume no shorts to ground? still have this wired so that Alt goes to b+ on relay, also from b+ on the relay, a 10g wire into the cab through the firewall, not the bulkhead, and spliced into the power feed/ammeter feed in the wiring harness...
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/06/19 06:43 PM

Originally Posted by Mattax
Its parallel but has a 14 gage Fusible link protecting 12 gage wires.
Need to place a 16 gage Fusible link where the 14 gage link is.
Then the 12 gage wires are better protected. The current 16 gage link can be eliminated.

Yes the ammeter will work as normal. There's only one path to or from the battery - and that's through the ammeter.


Okay, I understand. The 16 gauge FL on the alternator side was in the alternate 73 Charger/Coronet diagram posted a few pages back. From reading another thread I'd referenced earlier and that diagram, I had assumed that the 16 gauge FL would be necessary on the alternator side, to protect the smaller wiring between it and the amp gauge, if the alternator shorted out, or something else on that side of the amp gauge.
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 12:01 PM

Originally Posted by jcruse64
Nacho, thank you for the feedback.

The plastic is on the brittle side though, and that worries me.


are they available ? maybe similar to the A/B bodies ones ? well I allways try to get the fix as initally was, then make any upgrade. If is brittle for the charging leads, is brittle for the rest too, so If I was you, would try to replace the brittle parts as far is poible.... no matter if with used but better conditions parts ( donors, junkyards )

Originally Posted by jcruse64
Is there a disadvantage to separating feed to amp gauge OFF of the stock path to the welded splice inside the cab?? Will keeping the feed from alternator to amp gauge on separate path, after the terminal stud in the engine bay, affect correct readings of the amp gauge?

I've even considered cutting out the welded splice in the cab, running the new feed wire from the alternator into a buss under the dash, and then running separate black wires each to the ignition, fuse block, and headlight switch. I could also run the black wire to the amp gauge off this buss. This would be pretty much the same as the stock, welded splice, would it not?



will get into this later. finally arrived home
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 12:47 PM

ok, the idea about the 16 fuse link running to feed the splice into the cab even is not bad, will be actually just protecting in case of a short the ign system and MAYBE headlights ( just headlights, not even interior or parking ones ). I have heard the light switch gets a breaker inside, never have dissasembled one, but if that's true, then not even the light system is actually down the fuse link protection sicne got its own one. For the rest of parts, you already got the fuse box.


now, if you actually wanna remove the charging system completelly out of the bulkhead and still keep all the paths capabilities.... what about try this ?

-8 gauge wire up to amm
-The 12 wire originally running between splice and bulkhead now run between splice and amm stud, doubling the existant path between amm and splice. This will still feed the splice with TWO wires.

Would be great of course the wire lenght between bulkhead and splice is long enough to also reach the ammeter.

On this way you won't have to deal and work on the main splice, which usually is electrically welded, and is a better job that any splice home made.


and I still would use a quick disconect link, like this loop, to be able to conect and disconect anytime thiis ( for any reason ), cutting one side long to attach eyelet terminals reaching the ammeter, and the other side splicing into the engine bay wires

[Linked Image]



Attached picture Alt feeding COMPLETELLY the car, with parallel wires3a.jpg
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 01:36 PM

Thanks, Nacho!

Mattax noted that the FL on the alternator side would not be really necessary, but that it would be better to have a 16 gauge FL on the battery side, at the starter relay, to better protect the 16 gauge wiring in this system.

I saw your idea on the quick disconnects that you are going to put in your car, over on the other forum. I like that, and will be looking for a set of this wiring for my truck. I like your last diagram, and think this is what I will put in my truck.

Joe
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 07:11 PM

If using same quick disconect link I'm using remember you won't find diff gauge wires for red and black, so you will have to stuck with 8 or 10 gauge on both sides. You can still use the 8 gauge wire and splice in it a 10 gauge running to batt and of course the 14 fuse link.

That's JUST an idea about this, being clean, but there are a dozen of ways to make this. You can even install junction points to get power from there anytime you want. I.E. on black side at firewall to get power there from the correct side of the ammeter for a correct reading and feed accesories. This could replace the quick disconect link and the splice for the quick disconect link loop. I'm using quick disconect link because I don't want to drill my firewall or anything on engine bay to install junction points

[Linked Image]

You can even use a dual side stud installed on firewall and not use a grommet. Something like this:

[Linked Image]


Althought I like these better ( but is bigger than needed )

[Linked Image]
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 07:44 PM

I like that, too. I like the last one you show best, and it's probably not any larger, total footprint, than the others. Would make it MUCH easier to power a CB radio in the cab. I already have a single post, like the first one you pictured. I think I'm going to run a new 12 gauge wire off the12 gauge blue wire from the steering column harness to the keyed accessories side of the fuse box to this stud, under the dash, to allow for powering a USB plug that only has power with the key on.

Attached picture Feeder-Through-Terminal-Junction-Firewall-Battery-Studs-Bulkhead.jpg
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 08:16 PM

well, the stud on the round ones is 3/8" while the others are 5/16", so there is a difference. Eyelet terminals must be big, which makes a difference attaching small wires wire in them. I had once those in my hands and I recall the hole to be drilled on firewall must be something like 7/8" or so.
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 08:23 PM

Now, I don't get why would you need a dual stud for firewall like these to hook up a switched source into the cab... unless you want a switched source on both sides of firewall
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 08:23 PM

A 16 gage fusible link is needed when there are wires and connections12 gage or smaller before a fuse or breaker.
If you have a crimper, then you can make your own in-line connectors. Advantage would be if you wanted to change wire diameters or have one wire connecting to two wires out.
You can do the same with the ring terminals and a stud.

Parallel is convenient if the original bulkhead connector is OK.
If its toasted like Krautrock's '79 truck, then not so much so.

Parallel is similar to what Nacho shows above, and would be same as the optional Dart wiring if the original alternator feed was left in place. (The one with the ?)
https://board.moparts.org/ubbthread...6198/filename/1973-60Amp-Dart-color2.png

But there is a related strategy that is interesting to mention.
This is where the power into the cabin split before entering.
One power lead goes to the key switch.
The other power lead is for all the systems that don't use the switch. In other words, are always hot.
A version of this is used on the '76 A-bodies and probably other cars in that time frame.

One thing I like about the '79 truck ignition column wiring is that there are two hot wires. So this reduces the loads on the terminals.



Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 08:25 PM

Be best to find ones with a cover or shroud like was used on many of the alternator Batt terminals.
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 08:44 PM

Originally Posted by Mattax

Parallel is convenient if the original bulkhead connector is OK.
If its toasted like Krautrock's '79 truck, then not so much so.


sure and I mentioned. If terminals &/or bulkhead can't be or don't want to be saved, better simply run new paths out of bulkhead. Myself I rebuilt my electrical systems to original conditions THEN I made the upgrades ( parallel ), but that´s just because I wanted to keep/rebuilt the factory setup and keep it in working order. I got a good conditions bulkhead conector and new harness plugs to rebuilt my wiring. I made by myself the wiring, didn't buy the harnesses made.

Originally Posted by Mattax

This is where the power into the cabin split before entering.
One power lead goes to the key switch.
The other power lead is for all the systems that don't use the switch. In other words, are always hot.
A version of this is used on the '76 A-bodies and probably other cars in that time frame.


I think ( unless I'm missing something ) you are getting confused about shunted charging systems, where yes, in fact, the power got spliced before entering into the cab, for the main splice on 12 or 10 gauge, as long for the ammeter on 16 gauge form ( at both ends of the engine bay shunt ). So the bulkhead gets 3 wires entering from that wiring area. I think B and M/F bodies got couple more, but I don't think A bodies. Althought A bodies got a 32 circuit bulkhead panel for 76, but maybe also wiring the fuel pace system and some other stuff more at teh same time than the new Charging wiring network


Originally Posted by Mattax
Be best to find ones with a cover or shroud like was used on many of the alternator Batt terminals.


agreed, there are many options for these firewall junctions. I just posted couple of them. To each own choose which one. Making a google search will find them
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/07/19 09:23 PM

We agree!
First illustration shows how a parallel feeds to the main splice could be done with a terminal block in the alternator output wire and one fusible link.

Second illustration shows a seperate feed to the key switch to split load. Similar to having a relay or auxilery fuse box connected to the same terminal at the end of the alternator output wire. This is what I meant by borrowing idea from '76 Dart. Also like '79 truck with two feeds to the ignition switch - although without the FSM not sure which powers what circuit.

Attached picture 1973-60-Charger-Cornet-color-parallel.png
Attached picture 1973-60-Charger-Cornet-color-modified-seperate.png
Posted By: krautrock

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/08/19 03:28 AM

Just added fusible links to my wiring. Soldered both FL’s to a single connector so they can bolt to b+ on the relay. One FL for the alt wire, one going into the cab feeding the wiring harness in there.
First ran the truck without bolting the connector to the starter relay, so factory original routing but bypassing the bulkhead. Ammeter showed heavy charging for about 20 seconds, then went down to very slight charging. Headlights and all the cab electrics were strong, much better than before..thankfully.
Since i already wired it to connect to the relay, i wired it up that way, everything is good but i am getting a pulsing intensity through the lights, headlights and dash lights too. Like a metronome, slightly brighter then dimmer. About two pulses per second, don’t think it does it at idle but as soon as rpms go up it starts, doesn’t change frequency at all though.
Kinda weird. Wonder if its coming from the alternator or the modified wiring path.
Posted By: RapidRobert

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/08/19 03:44 AM

from the alt, check the brushes. EDIT (I'm assuming no electromechanical reg)
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/09/19 09:02 PM

Is there a source for those foam inserts in the engine bay-side of the bulkhead connectors? Mine crumbled when I took the connectors apart to clean them and remove the amp gauge lines. Do I just need to fill all of them with dielectric grease, plug back in and move on?
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/09/19 10:50 PM

Originally Posted by Mattax
Nothing to apologize for IMO.
I thought they were all Packard 56 - that's what I saw posted on jeep forums, here, Forabodiesonly etc.
Someone mentioned there were different types, but only when I was working on my '67's harness did I see that most (all?) of the '67 harness female terminals had the rolled edges for spring tension. Then when I replaced a terminal on the M&H repop engine harness, I found out for myself the Chrysler type (Packard 58 style) didn't stay in the connector housing for the Packard 56. confused Then I compared the terminals and fortunately I had saved the original harness. So I was able to use the original plastic terminal cover and all was well.

Chrysler also used 'twin locks' (steering column wiring connectors) and others which I don't know the names of.

PS. Slightly off topic, but related to the project. Inside the firewall connectors, there is a foam seal on the half with the male terminals. Detroit Muscle Technologies makes those. For the truck might have to contact Jim to see what he has or can make.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/10/19 04:44 AM

Read right past that one, lol. Thanks. I've seen that site before, but had lost the link. He has a few things I nee for my truck.
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/10/19 04:27 PM

Originally Posted by NachoRT74
Now, I don't get why would you need a dual stud for firewall like these to hook up a switched source into the cab... unless you want a switched source on both sides of firewall


I'm still thinking on this... why using this junctions for a keyed source being they really constant ?... maybe you meant using a relay activated by the ign switch but sourced from this junction?

Ammeter studs are also junction points if needed. Sure the firewall juntion is easier to reach and harder to beat.

Need to say NOTHING OF THIS will work propperly if you don't get the right alternator! The right alternator is what will save the ammeter! and some other parts of the electrical network

And, better if you dissasemble the cluster to check the ammeter conditions being tight to the internal shunt. Remember it got 50 year of stress and a badly balanced charging system from factory. If they began to be loosen, they are called to a problem when loads go throught.

I fixed a 70 Charger ammeter solding the studs to the shunt with lead just like solding wires. This consistent good contact will save from misscontact causing heat so won't melt the lead when load go through ( if happens )

Some ppl is about more radical electrical welding these studs LOL, even replacing studs.

read this ( I don't think being that extreme is really needed LOL)

https://www.dodgetalk.com/forums/showthread.php?t=252130

last time I read this, images floated on, not I can't see them anymore, dunno if you.

Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/10/19 07:19 PM

Nacho, what I had been thinking was to run the blue Accy wire from the ignition harness to a stud or buss (NOT the alternator or battery double sided stud), to allow to power something like a USB plug, on key on/Ign off circumstances. I'd have to take the other side of that stock blue wire in the connector, which goes to the fuse box to power fused accessories, to that stud or boss, so it would have power also, if I interrupt the connection at the ignition harness connector. Just thinking about it, and after a response about this idea on another forum, it would probably be better to go through relays, with power to the relays coming off the new firewall stud for the alternator.

I have the dash all the way apart already. This all started with wanting to clean the dash up and picking up some bulb holders to replace missing ones, and changing to LED bulbs. One thing keeps leading to another here as I find more stuff to do to the wiring and dash. I'm taking contact cleaner and steel wool and cleaning the posts on all the gauges, and the amp gauge is in good shape still. Also gently cleaning the back of the circuit board, first with a pencil eraser, and then with contact cleaner on the head of a Q-tip. Also painting the needles on the gauges.

What do you believe is a good upgrade over the stock alternator? Even though this truck used to have a snow plow and wrecker boom, it did not come from factory with either of those, so it is likely the original 60 or 65 amp alternator.

Joe
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/10/19 07:47 PM

it could be a good idea get an acc or ign1 juntion for some functions depending on your plans for your truck, Dunno on trucks, but E bodies and 71/74 B ( and I think laters Mopars too ) got a buss ( male prong ) for Acc source embosed on fuse box but unfused. Also got a batt buss there, both visible here:

[Linked Image]



Otherwise also got a fused acc source hanging out on the harness on bullet kind terminals.

About alternator, if you wanna go for cheap on stock form, no less than 80 amps alt used on mid 80s Mopars ( they use to source 45-50 amps iddling depending on pulley diameter ). They use to go into the $50-70 rate. Other options ( on stock form ) comes from TuffStuff guys. When I get money, I'd go for the 100 amps one, but they are rated on $200-250. Powermaster got a nice stockish option too claimmed to be able to source 65 amps while iddling. Then after that there are several nippondenso alternators what it works like originals, on same stock reg and wiring.

about ammeter, since you have the cluster out, please take your time on check internally the ammeter just to be sure studs are tight INTO the ammeter shunt, not just at cluster housing,
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/10/19 08:33 PM

Originally Posted by jcruse64
Even though this truck used to have a snow plow and wrecker boom, it did not come from factory with either of those, so it is likely the original 60 or 65 amp alternator.


It was probably better that way.
Almost always those things are attached to connector at the battery terminal or relay stud. really not much difference in this respect.
Here's why it might have been better he did not have a high output alternator.
Lets say the alternator can produce a maximum of 210 Watts at idle rpm.
With only engine load (field power and ignition) it can hold 14.5 Volts while supplying those needs. Lets say they add up to 5 amps. So 72.5 Watts.
If the battery needs charging, there is a maximum of 137 Watts it can still produce at that voltage, providing just under 10 amps to the battery. Assuming that's all the battery wants, the ammeter and all the wires can easily handle 10 amps.


Now lets have the engine idling when the tow rig is powered, and it wants 12 amps.
Well even if the battery was fully charged, the alternator can't provide that at 14.5 Volts.
But it can provide the 12 amps - or close to it, at less than 14.5 Volts.
If my math is correct, 12 amps demanded by the motor and 5 amps provided by the engine = 17 amps
210 Watts divided by 17 = 12.4 Volts.
Well the battery if fully charged will be around 12.8 Volts, so it takes over. Now the ammeter sees 5 amps discharge. Again the wiring is safe.

But lets say John tow truck operator increases the alternator rpms with a different pulley, or had an alternator that could produce more power at idle.
If it the alternator can now produce 420 Watts, what happens?
From the 5 amps go to the engine and 12 amps go through the ammeter. This acceptable - although arguabley if the alternator can supply that much power at idle, why send it all the way through the cab, the ammeter and to the battery?

This is getting to the crux of figuring out the best arrangement for the equipment.,
Really high draw equipment - like some winches - have to be placed on the battery.
They can draw over 100 amps when loaded.
With an alternator that produced a lot of power at idle, it might try to send 30 - 40 - 50 amps or more through the cab, main splice, ammeter and fusible link.
Or, almost as bad, maybe worse, is an alternator that produces high power but only at speeds above idle.
When the vehicle is driving down the road at 25 mph or better, its going to be able to produce close to its maximum.
This is when a high output alternator can be a bad thing for a drained battery.
The battery might try to suck 30, 40 or more amps from the alternator. On a stock alternator, it will max out and the voltage will drop and so would the battery demand.
On the optional 60 amp alternator, the engineers knew this could be a problem, hence the heavier wiring.
But still there are limitations in the ammeter and the battery itself.

This is the balance to be struck, bith in how things are wired and the selection of alternators.
It best for the alternator survival to have an alternator that is not maxed out very much. On the other hand, the maximum it can produce was a limiting factor helping protect the circuits and battery. My understanding is nowadays certain work trucks and motorhomes use a second battery and an 'isolator' for equipment that would otherwise stress the starting battery and alternator circuit.






Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/10/19 09:55 PM

Nacho, the truck's fuse box is not exactly like that. I have to get mine off the underside of the dash anyway, to get to and change the pink wire going to the dome light for the truck's bed. I'll look it over then. Fuse box already has some damage from the heater fuse spot. I've cleaned it up, replaced the fuse holder, and the blower switch, but this is another area I will want to improve on.

Will do on the amp gauge advice. Would brass be a better choice on the nuts for the 2 posts?

Mattax, thanks for the explanation. So it's really NOT so simple as just upping to an 80 or 100 amp alternator?
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/10/19 11:02 PM

Are you asking about the alternator ratings? That's right.
And rarely can we find anyone to give a full a proper answer about an alternator we're buying.

Whomever makes the alternator can rate the 'amperage' at whatever rpm and voltage they feel like.
Obviously most use a high rpm and low voltage to make their claim.
There's no standard. frown

This came up in a thread on speed-talk.
https://www.speed-talk.com/forum/viewtopic.php?f=20&t=41740

My takeaway is that within reason, more windings can be used to increase the strength of the rotor's magnetic field, and if the stator is matched more power is possible.
Of course more windings in the same space mean more expense and also less room for cooling....
A longer space makes a little more room for windings and cooling.
Tighter tolerances in machining and assembly can bring field closer to the stator windings.
Changing the way its wired from Y to delta will change the performance curve.
Some combination of the above accounts for the better overall performance of the squarebacks, revised squarebacks and the Denso alternators that followed the 'roundbacks.'

But the problem for us, the consumer, is we don't know if the rebuilder or aftermarket seller has matched the parts, or just improved the top end at expense of the low speed, and/or fudged the results a litle by playing games with the test voltage etc.

A couple example I can show of a higher rated alt having a drop low rpm performance are from AC Delco's catalog.
These are GM alternators but its nice they actually used to show the info.
[Linked Image]
Pay attention to the RPM and the voltage!
Being a pseudo-engineering graph, we don't know if the 12 Volts was the real test voltage or the nominal (common language) description of the alternator.
In other words this is 12 Volt Delcotron vs a 6 Volt generator.
(GM hated calling their AC generators 'alternators' like Chrysler did. laugh2 )
The other thing is the RPMs are alternator shaft speed. Usually 2 to 2.5 times the crank speed depending on the pulley set.
Here's another model.
I'm familar with these two because AMC used them both in the Jeeps. The 15SI was the preferred heavy duty unit presumably because of its good low rpm perfromance.




Attached picture tas_alt_15si_curve_type100.jpg
Posted By: Mattax

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/10/19 11:21 PM

The only complete Chrysler alternator curve I've ever seen is the one Nacho found in a box.

It shows the remanufacturer ran the test at 13.2 Volts.
But we can't compare that directly with the factory test for that alternator.
Almost always the shop manual test is done at 15 Volts, 1250 rpm (engine).
To compare, we need to know the pulley ratio, and then we can guestimate the performance curves at other voltages.
I just dotted in the 15 Volts without actually doing the math to illustrate the concept.

Attached picture Nachrt74-Late-squareback-output-markup.jpeg
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/11/19 12:44 AM

It's the Wild West out there, lol!!! Again, thank you for taking the time on this thread. I am learning a TON.
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/11/19 05:16 PM

Mattax has reached deeper into this than me. I just went to the basics, enough for me and my car. I just helped a bit. And maybe began this pro ammeter battle some years ago LOL. not because the ammeter could be the best or not, but simply because I found MOST of the ppl doesn't even know how the charging system works and how to read an ammeter.

about the diagram posted that I found, was from one of the alternators I todl you, a mids 80s replacement alt, sold under Beck-Arnley brand. I got it from Rockauto.

about those extra truck accesories and the isolation system... I'll have to learn too, LOL. Competition sound cars are on same deal.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 11/11/19 11:42 PM

Tested the fuel, oil, and temp gauges today, using the little hack in the latest issue of Mopar Action. Fuel gauge tested fine, but I could get nothing from the temp and oil gauges. I pulled the same 3 gauges from a '76 RC dash, and all 3 tested as working, and the needles are in better shape. I'm painting ALL the needles tonight. This truck was missing the voltage regulator for the gauge cluster when I bought it. I put one on it from Rock Auto, but those 3 gauges never worked. I've picked up one of RTE's versions of this to install.

I took the amp gauge out of the cluster for closer inspection. Both posts are solid; no movement at all in them. I'm reluctant to do any soldering, since they are still tight. I picked up some brass nuts to use for reassembly. On the back, are these black-ish squares the insulators? I have a can of Deoxit on the way. I will clean all posts, pins, and the spots of contact on the back circuit board area again, and will then reassemble everything.
Posted By: jcruse64

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 12/14/19 09:36 PM

Got slowed down on this project for a few weeks, but have the gauge cluster all cleaned up and back together and semi-pretty again, ready to re-install. I went with the double-post pieces that Nacho pointed out in a post, to re-route the alternator feed and amp gauge-to-starter relay out of the bulkhead connectors. Got everything under the hood in good shape and in some wire loom, to keep it safe and routed. Took the burned ignition harness connectors apart at the bottom of the steering column and made new connectors for them. I'm running the blue wire to it's own post, so I can run power from it to another spot to power a couple of future add-ons. Also repairing/replacing some bad spots in wires under the dash while it's all out, and have a question for all of you:

There is a welded splice in the harness, under the dash, for several orange wires. These are all for lighting, as far as I can tell. Mice chewed off one wire on driver side of splice, and was the reason I had no dash lights when I first got this truck. I soldered it to the splice, and got my dash lights back. I'd really like to improve my "fix" at this welded splice. I know the welded splice is much better than most other ways to make the connections with these wires in one spot, but would it be a bad idea to cut into this splice and redo it with a butt connector?

Joe
Posted By: NachoRT74

Re: Safely Wiring Accessories/Amp Gauge Re-wire - 12/14/19 10:46 PM

solding wires is quite enough. I'd use shrinking tube ( if you still have the chance to use it ) to seal the soldering spot, then tape everything back like it was. Nothing to worry about.


EDITING... just like this:

[Linked Image]
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