CruisingRam

My 1998 Laramie SLT Ram 3500 12V dually 4x4 is not charging. I have tried the old style voltage regulator- nothing. I have not been able to figure out why in the world this thing ain't chargin'. Though I have continuity at both sides of the 140amp fuse, when I just "hot wire" the altenator to the charging system- no charging, which to me, means there is a short somewhere that is not grounding or something. So I am contemplating just replacing the whole wiring harness, and seeing if that does the trick. If not then, the power distribution block, then maybe the PCM. Ya, I have come that far at this point.

I could use some really, really honest and reasonable on-line junk yards- where to look anyone?

dozer12216

Oh! for Pete's sake, take to a electrical shop and be done with it. Doubt you need a wiring harness or anything major.

CruisingRam

I took it to the electrical shop. After 4 hours of finding nothing to fix except to R&R parts, I made them give me my money back. I had told them to only go an hour if they just wanted to R&R stuff. I can do that myself.

wcbcruzer

Ok wait... How do you know it's not the alternator? I had a similar problem in our '88 4AGE Toyota Corolla. The dang thing just wouldn't charge! That engine is way more computerized than these 12v's, so I was starting to lose hope. I pulled the alternator 3 times until a light bulb went off in my head (the third time). It turns out it was the alternator... Long story short, the first two times I pulled the alternator and had it tested, it tested out ok. However, the confusion came because during the 5 min. test, the alternator actually worked. It was only after it ran for a little longer when it stopped charging.

48snowman48

try this one for parts:
www.car-part.com

pretty good site

CruisingRam

Thanks- that is great!

mobetta

I've also used http://www.uneedapart.com/

no affiliation,YMMV.

bj-666

sooo have you tried changing the alt or tracing the wires off of the alt to check for chafe. seems that is the place to start rather than just putting in a new harness or pcm

smokeum99ta

Did you start with the obvoius? Check alternator,fuses, batteries, battery cables and grounds at first. How about cleaning the contacts on everything. Its more than likey one of the above. Electrical stuff sucks when it gos bad, because it'll work here and there just to throw you off. Good luck with your search.

torquefan

The two smaller wires going to the back of the alternator operate the field circuit. With the truck running and the system voltage low, there should be close to 12 volts between those wires. The power comes from the ASD circuit and the ground comes from the PCM voltage regulator circuitry.) Check to see which one (if either) is missing. Shut the truck off and check for power at the heavy charge terminal at the back of the alternator, using a test light with the key off. There should be power there if the circuit is complete from the alternator to the battery.