I've been battling with my 91 Dakota 5.2L for a week now and I'm stumped. So far I've done the following:

1. Replaced Alternator
2. Installed External Voltage Regulator
3. Replaced Battery
4. Replaced Battery connections/checked for corrosion.

I'm still not getting any sort of charge to the battery. Battery reads 12.05 V, as do the two field winding posts on the alternator and the alt post going to the battery. The voltage does not increase with RPM as it should, just stays a constant ~12V.

I've since hooked the factory voltage regulator back up, still same situation.

No CEL at all.

Anyone have any ideas?

 

what was worked on last? save your list. one time i had a cable the the wires was not connected to the copper barrel, and a spark would jump.

 

I bought the truck about 6 months ago, haven't had a problem until the other day I noticed the voltage was reading low. The next day it wouldn't start. Charged the battery and put a volt meter on the battery and noticed the alt wasn't putting out any voltage as RPM increased. That's when I started with my list, so all of that has already been done.

 

I'm just curious here. How did you install an external voltage regulator with the stock alternator/wiring setup? I was always under the impression that the voltage regulator in the OBD I year trucks was controlled by the computer and would need to be bypassed and completely different wiring for it to work right. I went through that nightmare last year on a different truck

 

I followed a write up in the 2nd gen ram forums but you are correct i bypassed the internal voltage regulator wiring.

 

Damn, I wish I looked into that last year on my W-150. Would've saved some headaches.

As for your situation, does the battery take a running charge if you disconnect it and hook it to a set of jumper cables on another vehicle?? I had a similar problem one time when I removed a month old battery to change a fender and it got "accidentally fried" put it back in thinking it was good cuz it was new and it wouldn't take a charge past a nominal 12V until I replaced it with another one.

 

I've narrowed it down to the regulator. If I manually ground one of field posts the alternator comes alive and bumps the voltage up. Going to pickup another regulator tonight to see if that works.