cougar

Is their anyone out there that repairs or exchanges 92 - 93 automatic PCMs?
Mine is acting up. No grid heater preheat, only starts working after the engine starts.
Also the the alternator over volts after start up for a few seconds, then the wait to start light blinks on, the voltage goes to normal and the grid heaters start cycling down normally. Why the alternator is over volting is strange, it is on an external regulator.

1972RedNeck

Bad ground?

gyman98

Call me crazy but it doesn't sound like a pcm to me. I agree with bad ground or some other gremlin

cougar

Grounds are good. Thought part of it might be a bad crank sensor, so I replaced it. What a miserable job that was. And to prevent any more over voltage situations I removed the PCM from the auto shutdown circuit. Easy, just snip and ground one wire at the relay. I'll have to wit and see if the grid heater function has returned to normal. If it hasn't, I'll put in my spare PCM.

kensmachine

ther is someone that repairs the pmc I found on the net The do all kinds of emc just hunt the net

maybe368

Here you go: Dodge ECM Repair and Return - SIA Electronics ...Mark

Oldbull1997

Is the negative cable on your battery also grounded to the core support? Mine wasnt and it caused SO MUCH headache for me

cougar

Excellent, thanks Mark.

I repaired, replaced, and added grounds shortly after I bought the truck because of electrical gremlins. Also had my harness out a couple times trying to fix bad splices and broken wires. I need to just build a new harness and be done with it.

cougar

I put my spare PCM in this weekend and most things are working again. My spare was my original that had a bunch of problems. Some I fixed by re-soldering any cold solder joints I found and replaced a couple bad caps. The alternator and OD circuits don't work, but those are bypassed anyway by an external regulator and the Compushift.