I have a 1996 Ram 3500 diesel and was having shift problems. After checking the transmission wiring with a test light for power the alternator stopped charging and the wait to start/water in fuel / trans temp lights stopped working. Also now I have no power at the transmission. I've checked all connections, relays and the alternator. I'm thinking PCM problems but the closest tester is 30 miles away. Any ideas or information?

 

Should only see power at the trans for a few seconds, unless the engine is running.

 

What about the loss of charging and the lights?

 

Might be an entirely separate issue. Or, it might be related. Did you pop a fuse??

 

No all fuses and relays are good.

 

So, verify you are getting power to the injectors, and coil, at initial key on.

 

This vehicle is a 1996 12 valve diesel. Manual injectors and no coil.

 

Grab the factory service manual for your truck from here. Wiring diagrams are in section 8W. If you have a scanner that can read live data, see if it will even talk to the PCM.

 

Thank you for the information and the link. It will be very useful in the future. The problem was the PCM. I installed a refurbished unit and all problems solved.

 

Awesome.