Setting up an aftermarket AMP gauge?

1968 D100

I swapped my AMP gauge out for a Volt gauge a while ago after a dash harness failure. I realize now that it would be nice to have that function back.

My question is, can I run an aftermarket gauge pod from the fuse box Alt wire connections and see a true reading? Factory basically routes the wire through the gauge and I am wondering how I can reproduce that without hacking into my nice harness which I have ran a constant wire in place of the spliced connections for the old gauge.

Thanks!!!

As you know you want it in series to show ALL current flowing to/from the battery with the exception of the large wire on the starter. You would want it added into the main power wire coming thru the fusible link/past the bulkhead before that wire T's into seperate circuits (fuse/headlights/ign sw etc).

Can it be done? Yes.

Is there an aftermarket setup for vehicles that can do it? Not that I know of.

You'd need a current transformer setup to do what you want. Ever see those meters with the clamp you put around a wire to measure current flow? Something like that is what you'd need.

https://www.amazon.com/Search-Analog-Amm...nt+less+ammeter

I thought about adding a shunt-less analog gauge like the above
to my older battery charger that only has an analog voltage gauge.
A 0-60 or 0-100 amp full scale gauge would be preferable.

Simply running a loop of heavy gauge wire from the battery connection into the cab and back would allow clipping a Hall Effect amp metter on and reading amps. I have had a 0-300 ac/dc Fluke Hall Effect clip on probe as an accessory for my Fluke 87 multimeter that has worked well for a couple decades now. It actually has wires long enough to stretch from the battery to the cab of the truck.

There are also shunt meters:

https://www.amazon.com/MICTUNING-6-5-100...+volt+amp+meter

there are aftermarket and performanced full amp load ammeters in the market.

but why don't get an used replacement amm gauge for the cluster like it was and aftermarket underdash voltmeter ?

trust me, you don't need more than 40 amps gauge in dash... and if you do, something is wrongly hooked up. A discharged batt will never get more than 40 amps to be recharged. Chemicals are not that fast.

And if it does, something else is wrong, aside a fully discharged batt never must be charged back on car... not at least taking care of some other stuff

and if still you want an underdash ammeter gauge keeping the modified gauge on dash... here you got autometer options... everyone full load

https://www.ebay.com/sch/i.html?_from=R4...er&_sacat=0

you can also rebuilt your stock cluster gauge using a factory 60 amps unit and install the ammeter face from your D100

https://www.ebay.com/itm/1971-Plymouth-GTX-Roadrunner-Dodge-Charger-Super-Bee-NOS-MOPAR-Ammeter-Amp-Gauge/330851585796?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

althought can't recall if the D100 cluster is with needle pointing up or down. studs gap uses to be the same in all Mopar ammeters

then install an underdash voltimeter

or maybe this, 50 amps:

https://www.ebay.com/itm/1951-1952-Plymouth-NOS-MOPAR-Ammeter-Amp-Gauge/253258728043?hash=item3af765826b:g:bLgAAOSwyWZZWaoJ&vxp=mtr

here is one 80 amps

https://www.ebay.com/itm/NOS-Mopar-1972-1974-B-Body-ammeter-gauge-3592133-w-o-rallye/370842976147?epid=1217906272&hash=item5657f6bf93:g:P~0AAOxyfS1Ryyef&vxp=mtr

but everyone by now ith needle pointing up

it seems you can get 50 amps for your truck ?

https://www.ebay.com/itm/NOS-MOPAR-1962-1963-1964-1965-1966-1967-1968-1969-DODGE-TRUCK-AMMETER-GAUGE/262419279071?epid=1329984388&hash=item3d19686cdf:g:QZoAAOSwS7hXAToY&vxp=mtr

I reafirm you don't need more than 50 amps in dash, since the batt will never suck that load to be recharged. Chemicals doesn't work so fast

os this one... also listed for 68 truck ?

https://www.ebay.com/itm/NOS-MoPar-1961-1968-Dodge-D-W100-Truck-AMMETER-GAUGE-pn-1936914-2906072/332237625334?hash=item4d5ae7d7f6:m:mB0adFIq-jZjMsAOGn73PYA&vxp=mtr

50 amps, and needle pointing down

60 amps pointing up

https://www.ebay.com/itm/NOS-Mopar-1968-1970-Plymouth-Dodge-B-Body-Models-60-Amp-Ammeter-PN-2857005/272933360973?hash=item3f8c18954d:g:k68AAOSwxp9W4Gj~&vxp=mtr

NOS stock 68 truck... I guess 40 amps

https://www.ebay.com/itm/Mopar-NOS-1961-68-Dodge-Truck-Ammeter-Gauge-Instrument-Panel-Type-SA2-2906072/222222405458?hash=item33bd7ccf52:g:i~cAAOSwZVlXtJLK&vxp=mtr

and cheap aftermarket option, 60 amps

https://www.ebay.com/itm/Isspro-Ammeter-Gauge-2-1-4-2-round-0-30-60-Ford-Mopar-Chevy-Camaro-Old-Amp/372185409521?hash=item56a7faa7f1:g:9vwAAOSwYXVYz3k-&vxp=mtr

Cheap NOS from whatever car... 50 amps

https://www.ebay.com/itm/Mopar-NOS-Ammeter-Gauge-Markd-21259/152739801553?epid=1173302429&hash=item23900069d1:g:y6EAAOSwzJ5XWx1W&vxp=mtr

once again, to become it on the cluster replacement gauge reinstalling your original gauge face

and another NOS 50 amps unit

https://www.ebay.com/itm/NOS-MOPAR-DODGE-TRUCK-AMMETER-ASSY-2958549/183033742226?epid=1017921174&hash=item2a9da94392:g:ItIAAOSwKu9TxdSK&vxp=mtr

well... there are options

That is essentially the stock setup, but without the ability to read discharge current




Using a shunt could do the trick, if he put's it at the starter relay connection

As for all the OE type replacements suggested, don't bother to comprehend the question, ok?

Thanks everyone! I do have some stock AMP gauges that are in fine condition; so I could just do some switching around.... I was hoping to replicate the function but down low where I can see the connections more easily to monitor for problems if they ever occured...... I suppose I could just splice in with longer/modified harness.

depending on how did you modify the stock underdash harness to feed the voltmeter and bypass the cluster ammeter system, will rule what would you need to rewire that into the aftermarket ammeter. And that's something what only you know.

the deal is you can splice any wire coming from alt splice down the dash harness to the ammeter, but the wire to the batt MUST BE just one, the one coming out from + lead of ammeter to batt/starter relay stud. You can't get other one but that one between ammeter and batt.

In other words you can even run a straight wire between alt post and ammeter keeping the existant wires from the alt side in place BUT YOU CAN'T run the same between ammeter and batt. All the batt side of the wiring MUST GO THROUGHT the ammeter

I'll have to check, but I was hoping to tap into the tabs at the fuse box

How about an aftermarket ammeter? Good aftermarket ones are of the shunt type that do not require the full current to actually travel through the ammeter. I have a 100A stewart warner ammeter on my shelf with two tiny little connection poles because the full current does not travel through the ammeter.

I hit the snooze on this one. Sorry! I am back at it.

Nacho, I've wired the system as shown in the MADD diagrams where it goes from Alt to starter relay and then into the cab. THe only exception is that I do have connectors at the firewall.

It sounds like I cannot get the reading I want unless I go back to the old routing?

How about a shunt style gauge? How about a gauge under the hood for periodic checks? Would I simply enter between the Alternator and the Starter relay stud?

I do appreciate the notes.

the only way to get a full load ammeter working is getting the wiring up to the stock configuration. Any parallel path to the stock wiring jumping out the ammeter will eliminate the correct ( or any, if some ) amm reading. The ammeter needs to monitoring ALL the load coming in or out to the batt.

the only exception is a shunted ammeter, where the ammeter gets a built in coil amplifier able to move the needle with a minimun load going through based on a known resistence shunt. Shunted amms are a remote reading of the load going thought the shunt and they are wired like this:

otherwise, the stock wiring on full load ammeter is and MUST be like this.

( Bulkhead disposition is 71/74 B body based, maybe also E )

if a guy has an aftermarket amp meter, is it possible to add a shunt, and if so, what value would it be ? this would be on a custom built harness, nacho.

Ammeter with shunts are specific to be used with a matched shunt. They usually are sold as a set.

Mopar used this system since 75/76 and even could be used from a later model ( studs gap is the same ) but would need to get the shunt wire from the same car too.

I have a 78 F mody ammeter I'd like to use on my car just changing the face, but have no idea about how much must be the resistence of the shunt on this to convert my car on a shunted system, and by now have no found literature about this, maybe just getting a harness from this car with the shunt intact ( have no idea if I could get the shunt wire from another Mopar yet )

78 LeBaron ammeter

This is a 76 A body ammeter ( one year only ). Check the last pic and will notice the coil attached. This is an amplifier to move the needle with a minimum load, since these are not anymore full load ammeter, but is based on a resistor shunt with specific specs.

76 A body ammeter on ebay

You the man Nacho. Thank You!!

If you have an shunt type ammeter you can use a battery charger and a length of bare NiChrome wire salvaged from an electric heater to determine how many ohms the shunt should be to make the meter read correctly. Use a couple of electrical “jumper” wires with alligator clips at their ends to vary the length of NiChrome wire, making it a temporary shunt whose ohms you can vary. Standard industrial shunts typically are 100 milli-ohms or 1.00 ohms.