Haulin_in_Dixie

I got the engine work completed and started the engine. Found right away that the alternator was not charging. Next day went to troubleshoot the system. Manually exciting the alternator put it to full charge. Went through the service manual on the system. Checked the ASD relay to make sure it was functioning, ok. The 140-amp fuse was ok. Wiring was good. The regulator circuit in the PCM has gone out.

I mounted a two terminal electronic regulator on the fender apron. Wired accordingly and it charges fine. No codes set, no obvious changes to any system. Apparently the PCM codes do not set in until the voltage drops below a predetermined point. I have no doubt that the system will work fine. Only takes an hour or so to convert and the cost is only $11.00 from AutoZone.

Setting it up is real simple. You have two connectors on the alternator field and two on the regulator. Hook the two alternator terminals to the two on the regulator. Does not matter which one on either. There is just one more connection. The regulator terminals are on a small triangle mounting. Originally the Chrysler products had three terminals here, but the later ones only had two. One terminal is centered at the top of the triangle; connect this one to the ignition on circuit. That’s it, real simple.

This is a lot easier to set up than the old three terminal or grounded field types. The regulator that I used is for a 1979 D-100 pickup. A couple of terminals, some wire, and of course an inline fuse to the ignition circuit.

Haulin_in_Dixie

Put some stop and start driving on the truck today, about 120 miles. System works flawlessly, no codes set. 12v feed is taken from the ASD relay.

Haulin_in_Dixie

I neglected to put in the original post that it did not regulate well without a ground wire between the regulator and the alternator.

redramnc

Ground wires will get you every time. I once burned out a 10 gauge ground wire on the 100 A setup on my 78 W200. Went back with a 6 gauge from the block to alternator and #0 welding cable from battery to block to frame - never had another problem.

Now wiring the 6 gauge through the firewall to the back of the ammeter and back to the battery was a pain but worth it.

Always oversize wire - it may cost more in the beginning but it is well worth the added margin inthe long run.

Haulin_in_Dixie

Exactly, I used a #10 on mine. Been watching it for heat. I have yet to find the ground wire between the engine and body. There was one to the PU bed, but have not yet found one for the cab. I will be adding a cable just to make sure. I think the lack of regulation showed that there is a weakness there.

System is working great, for my road use I am glad to have the 1/2 volt lower voltage. Mine was just like Fords, with the 14.3 volt system the batteries overcharge on long trips.

BBWD

Haulin:

When you find the ground between engine and cab, please let us know where it is. I can't seem to locate mine either (maybe just stupid or blind, or both).

Congrats again on getting your truck runnin. Quite a job to do alone!

John (DH)