Headlights On, Engine Shuts Off, No Start

A novice in electrical testing looking for advice on what to test for above issue, have meter, test light. More details below if needed.

Saturday, went out to start, power but not enough to crank it over.

The alternator came off of a running car, but used, had coupon, so I figured I'd just replace. Put battery on charger, went to get alternator.

Replaced alternator, car fired right up, drove it to run errands.

Not 100% convinced it was the alternator, decided to replaced dimmer, as it would stick and I had a new one, and bypass ammeter.

Ran new charge wire/fuseable link from alternator to starter relay.

Black wire from alternator to bulkhead removed.
Original red wire from starter relay moved to where black wire from alternator used to be on the bulkhead connector.

Disconnected black wire at ammeter.
Ammeter red side had power seat connected there, which then goes to a circuit breaker.
Spliced black wire and red for power seat.

Car started fine, everything worked, test drove, put in garage, turned battery disconnect on negative side, out of habit from leaving it sitting over the winter.

Sunday, started right up, went out, ready to go, power but not enough to turn over.
Got a jump, got home, turned lights on, died.
Jumped again, idled fine, went to get meter, sputtered and couldn't keep it running, died.
Jumper pack out of juice.

Pulled bulkhead apart, looks fine, car is fairly original, and wiring is in excellent shape.

Charged an hour or so, started right up, 12 volts at battery, all electric items work, lights, seat, rear window, fan, no radio.

What do I check to find what is draining this battery?


All items new at the end of last year:
Battery, pos/neg cables, voltage regulator, starter relay, starter, msd dist/coil, eliminated ballast resistor.
Negative cable grounded to engine, paint removed first.
Positive cable with new solenoid wire ran inside heat resistant sleeve away from header.
Battery on trickle charger all winter.
The only thing I didn't replace is the horn relay and the headlight switch, they work.

12 volts at battery with engine running indicates a no charge condition.

JMO

Put the wire around with protection on it, bypass ammeter, leave ALL other stock wiring alone if in good shape.

When running, the battery should read above 12 volts if it is actually charging. I believe it should be above 12.6v

Alternator junk. Should be more like 13.6v running. Car is running on battery voltage until battery gets run down too far. Lights drew to much voltage and killed ignition system.

I think you have a single field charging system, and have a dual field alternator that is not grounding.
To make it compatible with your older single field voltage regulator, you need to ground the second field terminal.

Check if there is a plastic washer/insulator under the empty, unused field terminal on alternator, and change it for a metal one. (so it grounds to the alternator body)
Or you can make a ground wire connected to that empty terminal that grounds to the body of the car.
Could be worth a try !

Dominic, that sounds familiar, I think I had this issue on another car years ago.

The new alternator not only looks different, a raised square in the back, but it has 2 tabs instead of the one field tab, and what looks like a ground stud.

Maybe the second field s/b grounded there, although no instructions or indication provided with alternator.

I'll try grounding.

Found more info, now that I know exactly what to search.

https://www.forbbodiesonly.com/moparforum/threads/two-field-alternator-connections.113992/

So the options are:
lf using the mechanical voltage regulator, ground one field terminal.
If using a electronic voltage regulator, run original power from ignition to both the regulator and one field terminal. The other field terminal can use the same wire that went from the regulator to the field on the alternator.

Interesting that some mention the 'other' field connection tab appears to have a larger tab. On mine, it does look larger, or like the smaller tab was broken off.

Either way, I grounded it, if battery doesn't keep a charge it's still under warranty.
Then I will swap in an electronic regulator, which I believe I may have already.

I drove this Monday and today without issue, then coming home from work I made a stop.

Came out, dead battery.

I had a jumper box with me, started it and went straight to advance auto.

They put on tester, 20 cca, s/b 600, next part of test start, turn lights etc on, car died, jumped again, their tester stopped working so they couldn't warranty battery, system needed some code or something from the tester.

Gave me 2 options, leave battery there and they'll charge overnight and see if it charges, or come back tomorrow to talk to manager.

I said that's really just 1 option.

Put it in reverse to leave, died, still not going to give me a battery to at least get home?
It was getting dark and turning the lights on killed it.

By this point my jumper was dead so they brought out theirs, dead as well.

Guy jumped it with their truck.

I don't know if the alternator killed the battery, new or old, the battery was defective, or there's a short?

Wiring is in great shape, no new items, not even a radio.

Guess I'll bring it back tomorrow morning to see the manager.

I charged battery last night, went to advance auto first thing, guy actually called me earlier, they tested the:

Battery, fully charged.
Alternator, no voltage.

I asked if it could be the voltage regulator, the older guy said if it was the charging would spike and fall.

Below is how I grounded the second field on the alternator.

If I'm not missing anything here, I'm just going to return it.

It's 60 amp, the other one available is a 35 amp and it has 1 pulley, I'm thinking it also has 1 field.

Btw, for those who deal with advance auto, apparently you cannot return an item to a different AA. I guess it makes sense, but then again not because they can get me an alternator from another store by 5pm, but not return one to it.

Help me out here, if both the old new alternator, and the new new one I just picked up, have no rubber insulator and the tab cut off on 1 of the field connections, it is already grounded, yes?

Also, if changing to a electronic voltage regulator in the future, does this field connector need to be, say, un-grounded?

I was unable to find this scenario searching but I did find how to test for a draw and I do not have one.

It looks like it should be ready to go on the engine and work-
just screw in that second field terminal, including a metal washer(grounded), and plug the field wire into the field terminal with the rubber insulator.

If changing to an electronic VR, I think both terminals need to be insulated(un-grounded).
I would recommend upgrading to Mopar electronic VR because the mechanical ones can go bad