Ammeter bypass

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ebigga67

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I am doing an ammeter bypass and 1 wire alternator update. I’ve been looking at the MAD diagram and I’ve searched some threads here but I’m not getting it.

It’s a 73 Duster. I can’t figure out what terminal to drill out of the bulkhead connector, and if I’m supposed to eliminate the black charge wire form the alternator at the bulkhead and what the MAD guy is talking about splicing into that wire.

I’m close to selling the car over this upgrade. The car isn’t worth it. Unless someone can simplify this, it’s going on the block and sold as is.

I’m sick of trying to decipher the myriad of ways it can be done, and no one ever shows exactly what wire to remove from the bulkhead connector.

I’m frustrated. Nothing is worth this crap.

TIA for any help.
 
Wow, it's not that hard. Get a meter and probe the wires. Theres a fat red one from the bulkhead to the battery, and a fat black one coming from the alternator to the bulkhead. Those go inside to the ammeter. Those are the ones they want you to bypass around the bulkhead connector and run thru the firewall inside rubber grommets. Go get a nice laminated color schematic from www.classiccarwiring.com

As far as a 1 wire "tractor" alternator goes, your on your own.
 
IMHO
You should not have to remove any wires from the stock wiring.

Running a wire directly from alternator to starter relay post that goes to the battery will do the same thing. It also gives you two paths through the bulkhead connector to power the car.

You should add some wire protection (ie fuse/ fusable link etc.) to that wire.

At some point in the a body line I understand that the Ammeter became a remote sensor device so the wire from the alt to the battery does not enter the car.
 
First, do you have a factory manual? If not run over to MyMopar and download one for free. It's there because of some of us on here. There are two sections, the "chassis" and the "body."

DISCONNECT the battery ground for safety

About a jumper wire. You need to have either a fuse or fuse link in that wire if you do it that way. Crackedback on here sells a nice made up kit

But a jumper wire "aint that easy." You STILL need to make sure the big red and big black wires going in through the firewall connector are in reasonable shape, as they still act as "infeeds" for power INTO the pass. compartment.

Also, pull the ammeter wires, bolt them together, and tape off.
 
Also, pull the ammeter wires, bolt them together, and tape off.
IMHO if everything is in good working order and you're not pulling massive amps off of the OEM wiring you can leave the ammeter connected.
 
I suggest leaving all the OEM wires in place, bypass ammeter and run the charge wire. Check bulkhead for damage and any required repairs (black wire usually gets roasted) and move on. No cutting of the OEM harness.

Sort of what Del @67Dart273 said... :lol:
 
Update: there is no electrical system in this car. What’s there is garbage as far as the changing system goes.

I want to eliminate the voltage regulator plus all that nasty wiring and clean up the engine bay.

After looking at the MAD drawing for a bit, I can’t under and why he wants to feed the welded splice from two sources. That seems stupid to me.

For the moment, I have left one of the wires at the welded splice (the one going to the ammeter I think I’m not looking at the car right now) just taped up and I’m feeding the splice from one wire coming off the starter relay.

If this won’t work, let me know. I can’t see a reason why it won’t, why it’s not safe and why you’d want to feed that splice from two different sources.
 
It makes a "parallel fed" and in effect makes the wiring larger. There are other ways to do this. Remember, the 1/4" wide spades in the bulkhead connector FAIL at 20-25A. I used to maintain/ repair HVAC, and a typical electric furnace/ heat pump uses lots of those in the heater. The default heater elements are nominal 20-25A and failure of those flag terminals is NOT rare

And here Mopar was using them for 37-60A or more................

My first bulkhead connector failure was on my 70 RR way back in the early 70's
 
It makes a "parallel fed" and in effect makes the wiring larger. There are other ways to do this. Remember, the 1/4" wide spades in the bulkhead connector FAIL at 20-25A. I used to maintain/ repair HVAC, and a typical electric furnace/ heat pump uses lots of those in the heater. The default heater elements are nominal 20-25A and failure of those flag terminals is NOT rare

And here Mopar was using them for 37-60A or more................

My first bulkhead connector failure was on my 70 RR way back in the early 70's


I have a question because I need to do this to my car this fall. My question is IF you eliminate that .250 spade can I keep the ammeter? Or should I eliminate both the .250 spade and the ammeter?

And if I do that do I still need a parallel feed.

Ok, that was more than one question.

Sorry for the derail.
 
IMHO
You should not have to remove any wires from the stock wiring.

Running a wire directly from alternator to starter relay post that goes to the battery will do the same thing. It also gives you two paths through the bulkhead connector to power the car.

You should add some wire protection (ie fuse/ fusable link etc.) to that wire.

THIS.

and toss the GM one-wire alternator. Keep the stocker. You're making this harder than it needs to be, just to downgrade!
 
Some guys (I did back in the 70's) just eliminated the big red and big black wire connector terminals, drilled through the connector, and ran larger wire straight through. If you don't mind that it works OK. Eliminating the ammeter is up to you.......depends on the condition of it, and how much alternator you intend to use. Anything more than 60A I would bypass it.

Go over to MyMopar and download about a 72 service manual and look in the diagrams (likely the larger cars, not A bodies) for the optional 65A alternator wiring. This was commonly known as "police / fleet/ taxi" and was in effect a connector bypass but kept the ammeter. Notice, in the diagram, they fed larger wire through the firewall SEPARATE from the bulkhead connector. One of the old wires (red I think) was taped off and not used after that.
 
After looking at the MAD drawing for a bit, I can’t under and why he wants to feed the welded splice from two sources. That seems stupid to me
Like 67dart273 said, by feeding the splice with 2 wires each wire only has to carry 1/2 of the current. The bulkhead connectors also only carry 1/2 the current that way too.

No real reason the bypass the ammeter.
Unless you have massive accessories attached to the stock wiring or it is defective and a super wizbang alternator

1/2 the current to the splice will go on one wire the other 1/2 will go through the ammeter on the other wire.
 
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With my 64 Valiant Vixen, for example, All I have that's not stock is an H4 halogen headlight upgrade with @crackedback's really nice headlight harness and relay package, a 55 amp later square back alternator, electronic ignition upgrade and a nice vintage style stereo AM/FM/CD/Blootoof/AUX/MP3 with NO exterior amplifier. All of the wiring is in great shape still and the ammeter works great. I have no need or interest in bypassing it. I've talked about with Del a little, but I really don't think it's necessary. Might do it down the road a piece, I don't know. I might not.
 
My ammeter doesn't work on my Duster for whatever reason. I unbolted it and spliced them together with a 30a fuse. Is the fuse needed? I don't know but that's what I did.
 
Did you manage to solve the issue? And thank you all for the answers in the thread! I am a beginner auto electrician, and I have a case with an old Duster where I need to find a reason for the electrical harness issues. And I’ve tried everything I knew already.
 
My ammeter doesn't work on my Duster for whatever reason. I unbolted it and spliced them together with a 30a fuse. Is the fuse needed? I don't know but that's what I did.
Depending on how big the alternator is, and how much load is on the system, 30A "may not last"

That in short is exactly what is wrong with the OEM design. The wiring is not large enough, the bulkhead terminals were never designed to handle that kind of power. So you can't protect the wire by "conventional" fuse sizing, "it just won't work"
 
Did you manage to solve the issue? And thank you all for the answers in the thread! I am a beginner auto electrician, and I have a case with an old Duster where I need to find a reason for the electrical harness issues. And I’ve tried everything I knew already.

Being an electrician is what I wanted, and now I put all the power and attention into education. But sometimes it’s just too difficult, if not impossible, to find the answers yourself. I already have a good salary, and the Salary is based on the industry of employment, but I feel that I need to become better to be known as a good specialist.
 
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