Got in my truck this evening leaving a seminar and, no charging. I think the brand new Mopar voltage regulator crapped out already. Barely made it home with dim headlights. Glad I have that yellowtop!

 

I will check the voltage on the blue wire later today. Have to go back to the PCM VR for now.
I don't need diagnostics, I need an exorcist!

 

Sorry to hear that you having such issue with your charging system. This is one of my paranoid fears as well with converting to the 93 wiring system.

That is also why I have kept all my 89 stuff, wiring, steering column etc. If things get too bad I can always swap back to the early, mostly trouble free system.

 

I guess wiring harnesses age also. At 410K on the clock I guess I can expect issues.

 

I wish I could find a new engine and a new cab harness for this truck. It would same me so much aggravation in the end.
Want to try to find a used set in good shape that I can go through and check wire by wire and then swap it, but that might be more of a hassle than just fixing my junk.
Frustrated.

 

You know, with the value of these trucks, I wonder if someone like say Street and Performance or similar vendor who converts late model EFI wiring harnesses for conversions would be interested in producing new harnesses for our trucks?

S&P isn't the cheapest, there might be another vendor who would take it on, but likely no one has asked them to look into it.

 

I think ive got both harnesses from previous salvage trucks I bought, but it was a '92 auto 2wd, ive got 3 earlier ones relative to my trucks, but your right, fixing what you got will be the best in the end.

 

Hooked up an older Mopar VR I had and it was putting out between 15.5 and 16 volts (one second fluctuations). Pulled that harness and went back to the PCM and needle probed the blue wire coming out of the alternator, exact same readings, same fluctuations and all. Then connected the negative probe to a chassis ground and the voltage came down a bit. Rechecked all my grounds and checked the battery terminal connections for the umpteenth time, this time got a tiny bit of movement on the negative terminal. The clamp is bottomed out, so I took an old pair of vise grips and pinched the terminal hard, 14.4 volts, steady as a rock. I should be kicked. I haven't road tripped it yet to make sure, but I feel like quite the idiot.
When the check engine light first came on I ran the codes and it said "low voltage". That sent me on "Mr. Toad's Wild Ride" down the wrong path.
I hope this is the answer, only time will tell, but a part of me hopes I was not that stupid.
If anyone came to me with the symptoms I had I would have told them to pull the battery terminals and clean them first thing.
Humbling.

 

Glad you got it figured out...even if it was such a simple thing. We have all been there, overlooking the most obvious thing because we are "sure" it's fine.

 

This is exactly why I use batteries with the threaded terminals, so much easier to maintain. I find electrical problems frustrating to say the least, glad you got it figured out.

 

A wise old man told me something many, many moons ago.....


KISS.... no not Gene, Ace, Peter and Paul....

Keep It Simple Stupid..

Anytime I do any type of repairs that involve electrical... I look for the simple stuff first... then get more crazy wabbit afterwords...

Hope / Glad you got it worked out.

 

what a great ending......volt meter my best friend/tool, sometimes our problems are solved looking from outside the box, and this is the stuff I wake up in the middle of the night, and start dwelling on, and sometimes it gets fixed just laying there thinking about it.....at least you should sleep tonight/good job

 

I believe in sharing with full disclosure so that others may save themselves headache by learning from my folly.
The good news for me is I now know my charging system pretty well now!