Two weeks ago I had my tranny rebuilt by a well known guy, 3 clutch converter all new billet parts ect. He also installed pillar gauges on my truck, everything seemed fine..couple days ago I opened my hood to check things out & noticed one of my batteries lost the cap on top of the battery thinking it was bad I took it back to the place & had it exchange under warranty battery was very hot so we checked out the alternator putting out 18.5 volts "over charging" so I replaced the alternator checked it again now over 19 volts. PCM bad ??? could this have happened when tranny was rebuilt or when the gauges installed

 

Nope, most likely not. Sounds like a bad PCM. There's a very small possibility a wire could be shorted on a trans harness and fry the pcm but their would be no way to prove that without a damaged connector, trans not functioning correctly. Sound like you've just had some bad luck!

 

Did I miss something, I am new to dodges, or anything run by a computer for that mater. So... since when does the PCM/ecm or any cm have anything to do with alternator output voltage? I know GM Alts have built in Voltage regulators, and that older cummins powered dodges have an external VR, but as far as I know they are independant of the computers. Tell me if Im wrong.

 

every dodge pickup from 94 up (that I know of, Not big on 1st gens) is externally regulated by the PCM, and the important piece in this puzzle is the fact the PCM is also the TCM For instance if your 01 or 07 for that matter starts shifting funny, or starts charging unusually you could most likely clean the grounds on the PCM and fix the problem.

 

OK ill bite....whats a TCM?

 

Transmission control module, in dodges also known as the powertrain control module

 

Transmission cm ok i figured it out.

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Your making that 12v engine in my shop look better and better.

 

As I said before anything 94 and newer is externally through the PCM.

 

or a P-Pumped 24 valve conversion.

 

Failures I guess you could say are not all that common. I guess they seem more common to me for the simple fact we work on these trucks day in and day out and run across it more often