So I am having a hard time getting a consensus with the charging aspect of my E-Body. My local Mopar/Electrical guy tells me 100 AMP Alt with Chrome/Red Regulator and Bypass wire. Nacho and Mad says more or less the same thing, but I called a few Mopar harness places and many on this forum suggest to stick with stock charging system.

I welcome your opinions or what you are doing.

I have a 318 Cuda I am converting to 440 ECU and I have a stout stereo and that's about it. I plan to do dash/internal work next winter so right now I want to get the engine and front end setup while the engine is out.

1) Should I stick with a 60AMP Alt and then run a ALT/Relay bypass wire just for good measure?
2) Should I take this chance to upgrade to a 75-100 AMP ALT and run the bypass and get a better Voltage Regulator?
3) Should I do the complete Bulkhead/Bypass/Disable Ammeter as Mad suggests?

I am hoping to get the engine work done without tearing up the dash just yet but I am not clear if the 60AMP ALT will push the ECU and badass stereo. Moreover, since I have some sketchy wiring connections under the dash, it seems that an ALT/RELAY bypass wire would help me reduce some risk before I do the dash work.

Any thoughts?

Sorry for the long post. I am curious what the REAL answer is for me and what you guys are going.

-Steve

keep the stock alt. and regulator BUT bypass the original ammeter.
Worked great for me,still looks original.

(as you know) many ways to go. (1) I would clean ALL terminals/connections especially the bulkhead (wire brush on the male terminals/NAPA 725147 male terminal to clean the female ones). (2) do Nacho's 2 wire bulkhead bypass. (3) keep the ammeter (4) relay the stereo & if desired maybe the lights/heater to the alt (good idea). (5) keep the current alt & if it dies then upgrade to 85 M body 78 amper or a Denso (far better but diff brackets needed). (6)koppercoat (sp) on the terminals. You want to keep the ammeter needle as close to 12 0'clock as possible & the solution is to via a relay(s) power all devices right from the source (the alt). This keeps excess current out of the bulkhead/underdash EDIT that is not a long post! (& I enjoyed it) & the reg (electronic I am assuming) will be fine

Awesome advice and it seems to be the best approach long-term. I plan to take the dash apart next winter and install new harnesses, connectors, etc. What do you think about a phased approach?

(1) Clean ALL terminals/connections (2) Install a Bypass wire through the bulkhead to simplify future dash work (see diagram) (3) keep the ammeter (4) Use 60 AMP alt for now (5)koppercoat (sp) on the terminals.

What's the AMP draw from the stereo? How big is the recommended fuse that feeds the power supply to you amplifiers?

The problem with Mopar & Denso alternators is that they don't put out a lot of amperage at idle, or even at 1200 to 1500 or rpm for the Mopar type.

Phase 1 will bypass the ammeter & keep some of the load out of the bulkhead because of the parallel bypass. Phase 2 will do the same thing but restore the ammeter. All good there. Critical would be to (1) relay the stereo so it gets fed from the black wire between the alt & the firewall (2) clean/koppercoat all terminals/connections

These are all good ideas to do the parallel bypass if you are using the original wires and amp gauge which is 40+ years old at this point. FWIW, a 100 amp alternator can be made to work on factory wiring/ammeter just fine IF the wires everywhere are in good shape (or new harness) and you keep some things in mind:

- part of the excessive current being pulled through the harness/bulkhead is not due to high alternator output but actually do to low output (at idle mostly) where the battery would discharge and the charge sharply once the car took off. If the factory alternator put out good charge at idle, the battery would not discharge and then have to 'catch up' when the engine picked up RPM's. So my point is for stock type loads and clean wires/terminals having a higher output amp will place the same or LESS strain on the charging circuit wires.

- You can get into trouble when you don't consider where you pull any non stock electrical loads off the charging circuit. Think fuel pumps, fans, hi current amps, etc. People tend to want to want to pull power from the battery which is the most obvious choice. However, this will result in all this additional load being pulled through the entire charging circuit and bulkhead while the car runs. This is what burns up wires and makes people fear the original design. These large, constant loads MUST be pulled from the alternator stud. This will result in NO additional load being pulled through the harness/ammeter IF the alternator can meet the demands. Additional load would only flow through the harness in this case if the alternator couldn't keep up and the battery had to discharge to make up for the gap.

I run a 100 amp squareback on my Charger with an original charging circuit. My harnesses are all new and my ammeter has been rebuilt. My currents pulled through the harness (ammeter) are LESS than they were when I had the 60 amp version. The only time I get a wild needle swing in either direction for more than a split second is when I first crank the car and the alternator has to replenish the battery. Oh yeah, and I have electric fans. I have confirmed this with clamp gauges and the ammeter. I can run A/C, electric fans, radio, lights, etc and my charging wires don't get even warm. So yes, it can be done without the bypass but the bypass is probably a 'safer' option if you don't know the condition on your wires end-to-end and understand how the charging circuit works.

One last point, I wouldn't worry about relaying a stereo. If the stereo is modern and you aren't installing external amps, the stereo current draw will be negligible. I have a 50X4w stereo that draws maybe 2-3 amps if I crank it way up and it's hitting a beat. In fact the factory fuse on it is a whopping 5 amps. I can sit in the car and crank the thing up to where its making my ears bleed and the ammeter barely moves with the car OFF.

cjskotni, Thank you for the detailed reply. I had the pleasure of speaking with Mark from MadElectrical.com for about 3 hours on Friday and he taught me far more than I will ever remember. I ended that call and thought I knew exactly what was needed; Single Wire, Bypass, replacing ammeter with voltmeter, and new relays for lights and everything else above-and-beyond stock. Of course none of that is stock and most of it is obvious to even the casual observer. His argument is that a "driver" needs to be more modern to be safe whereas a fully factory car should be (I am paraphrasing) parked and babied due to inadequate charging and electrical problems. Is yours a daily driver? Do you take long trips with it?

I am replacing every wiring harness (as I restore) and am willing to do a bypass since it will be nearly indistinguishable to the casual observer. Based on your experience it sounds like that should be more than enough and still look pretty stock.

However, now Mark has me worried about low Idle volts and headlight strain through the bulkhead wires. On Friday, I was convinced I needed to get the 440Source Denso Alternator conversion kit and hide some light relays under the battery tray to move all the high loads up to the engine compartment. I was convinced, but hesitant since I would be missing a firewall-mounted voltage regulator and a trained eye would see the wires running under the battery for relays.

Good Lord this is difficult!

Anyone else think the 1-wire conversion and light relays are the best/only way to go?

Cksjotini, I don't want to steal the thread, but there are a lot of people in the same boat as the OP, and just are not sure which way to go. I'm kinda like him in that I thought I knew what to do, but now I'm not sure. So if you will let me tell what I have maybe we all can get something done together.
I have a 71 RR ,I want a completely stock look, but with some modern stuff hidden out of sight.The harness firewall forward is new, I had a 60 amp stater put in the original Alt, and I had the amp meter studies welded. The car was protected all its life and the inside harness is in like new shape. The only extra draw is a BIG stereo amp I installed under the package tray out of sight. It has a built in 20 amp fuse for each channel. I ran a big power wire to the engine compartment, and now I'm not sure where to hook it up.
I was going to hook it to the stud on the starter so it wouldn't be seen, but after reading all this should I run it to the alt?

In my earlier post I had assumed that stereos drew alot of power. If that ain't the case then you could likely get by with powering it from the eng side of the bulkhead but I would definitely do Nacho's parallel bypass & you could drill thru the bulkhead & wire it straight thru for a hidden look. with good/clean connections/terminals the #1 problem is the bulkhead & it's a good idea to relay as much as possible directly to the alt especially the headlight/heater. this keeps the ammeter honest. I would stay with the OE type alt not a 1 wire.

So after 3 hours with Mark, I think I can answer the Stereo/AMP question at least with his recommendations. I too have a Big amp bolted hidden under the package tray and I ran a hefty wire up to the battery. Mark's recommendation however is NOT to connect these things to the battery but to a wire distribution that is central to the overall charging system. His opinion is that you move to a 1-Wire or Bypass system so the "central" connection becomes the stud on the starter relay. The regulator will see this load and adjust power accordingly without traversing the bulkhead connectors or underdash weld. I attached a drawing he asked me to make while he explained it. Unfortunately, by default we don't have a good "central" point like this so connecting things to the battery forces the resulting charge to traverse the wiring harness, underdash weld and gauge. Moving to a 1-wire or installing a bypass puts this central point on the starter which means it will take the power directly from a regulated alternator charge unless the car is off, then it pulls from the battery.

is your amp switched? meaning that it has a built in relay to power it down when the radio is off? if not then you need need the fuses as well as a relay. I would connect it to the lug on the starter solenoid where the battery and alternator connect to, the send the power wire back to the amp. the relay should be controlled from a key toggled power source, meaning that its only hot when the car is in the run position.

Yes, it is switched, it has a separate wire that goes to the stereo, and only comes on when the stereo is on. Do you mean hook to the starter relay?

ok then skip the extra relay and just get power from the starter relay lug where the alternator and batter connect. I would also bypass the ammeter in the dash. and for good measure run a new wire from the alternator output to the starter relay so you create the parallel circuit.

On that NAPA terminal 72517, is that a terminal with some brush bristles on it? I call the NAPA store and they said it was just a terminal.

Great advice there. The idea of moving the central power source to the starter stud (with the bypass or 1-wire conversion)is better for all new power draws especially the larger ones. However, we need to make sure we create that parallel or rerouted link to the ALT. If you don't you will put the bulkhead connectors, gauge and underdash weld under significantly more load since ALL charging goes through those points. Hooking it up to the battery does not solve things. This should mitigate overload risks to the weaker links but it still does not guarantee good idle RPMs or good power regulation however which is why I still question staying with the legacy regulator versus a single-wire.

there is nothing wrong with the legacy regulator as long as it has a good ground. the one wire alternators have the same regulator built into the alternator, the mopar ones are just on the firewall.

we run this conversion on our cars with the serpentine belt kits we do and we have up to 165 amp alternator as an option. its crucial to add the parallel wire to the circuit otherwise you can melt down the entire wiring harness if you have a short somewhere. a nice 6 gauge wire will do wonders in bypassing the current. this however will not mitigate power fluctuation when using corroded connectors and old wiring in high power applications like head lights.

Jerry,

So I agree with your statement about the regulator. My question is the intelligence of it when the bypass wire is added. Since the pathing of the regulator is through the bulkhead connector, into the gauge then back out the bulkhead and into the starter relay will it adequately "see" all the load? Also, will the direct link from the ALT to the Starter Relay pose an overcharging potential on the battery since there is no regulator between the ALT and the Starter relay?

-Steve

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cjskotni, Thank you for the detailed reply. I had the pleasure of speaking with Mark from MadElectrical.com for about 3 hours on Friday and he taught me far more than I will ever remember. I ended that call and thought I knew exactly what was needed; Single Wire, Bypass, replacing ammeter with voltmeter, and new relays for lights and everything else above-and-beyond stock. Of course none of that is stock and most of it is obvious to even the casual observer. His argument is that a "driver" needs to be more modern to be safe whereas a fully factory car should be (I am paraphrasing) parked and babied due to inadequate charging and electrical problems. Is yours a daily driver? Do you take long trips with it?

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These is nothing wrong at all with doing the parallel bypass and converting to a volt meter. It gives you the flexibility to run much larger cable on the charging circuit which is never a bad idea. I was making the point that a restored factory type circuit with even a hi-amp alternator can work just fine if you wire it correctly. When I pay nearly a grand for factory replica harnesses + gauge rebuild, I am not splicing and drilling.

FWIW, I have taken this car on 50 mile trips so far and once the alternator has topped of the battery after startup, it stays damn near dead center all the time. This indicates little to no current flow to/from the battery. The constant discharge/charge cycles of the underpowered factory alternator is what kills the wiring and makes heat up and burn.

Another note that relays will NOT (repeat WILL NOT) fix and underpowered alternator charging issue. Relays are designed to provide a more direct path for current to flow from the charging circuit to the powered device (headlights) thereby providing a minimal voltage drop which gives brighter headlights. This also has the effect of taking the load off of the headlight switch which will allow it to run much cooler and longer. However, the relay will lower the resistance of the headlight circuit (due to the elimination of the in-line switch + small wiring) which will lead to MORE current draw from the relayed device.

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I have a 71 RR ,I want a completely stock look, but with some modern stuff hidden out of sight.The harness firewall forward is new, I had a 60 amp stater put in the original Alt, and I had the amp meter studies welded. The car was protected all its life and the inside harness is in like new shape. The only extra draw is a BIG stereo amp I installed under the package tray out of sight. It has a built in 20 amp fuse for each channel. I ran a big power wire to the engine compartment, and now I'm not sure where to hook it up.
I was going to hook it to the stud on the starter so it wouldn't be seen, but after reading all this should I run it to the alt?

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You would want to take the power for that amp from the alternator charging stud....provided you listen to your music mostly when the car is running. When the car is off, the current to drive it will then have to come from the batter which will lead to a long trip from the battery, thru the bulkhead, back thru the bulkhead and back to the alternator. Putting the power cable at the starter relay would not be a good idea.

If your amp is that big, you are going to be disappointed at the results if you crank the music up. I'd plan on going to AT least a 100 amp alternator. For your case, I'd also recommend a capacitor for the amp to help smooth out the power draw (and voltage drops) from 'beats' in music.

A parallel bypass wouldn't be a bad idea for you as it would provide a solid path to power the amp regardless of whether the car was running or not. However, if you are sure your wiring is that good and you keep in mind the path the current takes running vs. non-running, you should be OK.

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I would stay with the OE type alt not a 1 wire.

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Agreed, unless you are going to a modern design alternator, stay away from the one-wire retro crap.