Archived electrical problems 94 auto 4x4

[Diesel Gopher]

Ok, Ive posted before on some of these topics, today I am at my wits end. In the past year, I have replaced the transmission temp sending unit, TPS, added the ATS noise filter (to solve the OD lock/unlock problem) and eventually put in a 1000 ohm resistor in the temp sending units place. Now I have spent weeks working on the no charge problem that developed in early Dec. After testing the alternator, it was weak (not shot), I replaced it any way. That didn't solve the problem. I also lost the tach and speedo. Next went in a new PCM, when I first started the truck it was charging a little over 14 V, tach was functional and all looked good. After letting the truck warm up a few minutes, when I put it in gear the tach went dead. Fed up I ordered and waited for a new crank sensor, installed it and started the truck. Charging appeared normal, tach worked, until I put it in reverse to back out of my drive way. Tach went dead, charging now appears low like it did when this first started (8 V or so) and I am at a complete loss as to where to go next. All the grounds were scrubbed clean last fall (during transmission shifting problem)and I am currently rather angry and very frustrated. Any and all help is greatly appreciated.



Matt

 

[Joe G.]

I would look for a corroded connector somewhere. It sounds like a bad connection or broken/loose wire. As you have probably realized by now throwing parts at it is not working. It's time to do some troubleshooting to find the problem instead of replaceing things that might be it.



If you don't have a service manual you need one because of the wiring diagrams. Also a meter so you can check to see where the voltage is good and where it is bad when the problem happens. These things are not easy to find.