One of the reasons I try the local parts stores first....... If I get a bad one, they can have a replacement generally the next day...... two at most. They tend to be a bit more expensive, but, if you run into the problem you are..... I can't be without my truck for weeks at a time. It's the only thing I have to drive.

 

To be safe you should be disconnecting you battery before swapping the PCM's.

 

So I have went through 2 separate PCM sent by Car Computer Exchange and all of theirs, the instrument cluster does not work. Plug in the junkyard PCM and instrument cluster works. 95% is telling me it's a PCM problem. But to check that 5%, does anyone know the wiring diagram for how it communicates with the instrument cluster? Im wondering if there is a bad ground somewhere. Ground wire locations? This is seriously pissing me off and I've been waiting for a month to try and solve this....

 

What's the build date on your truck?

In 98, dodge radically altered how things worked. Instead of the gauges reading directly from the various sensors, the sensors report to the PCM, the PCM then communicates with the central timer module, which sends signals on to the cluster. Basically, its a little network in your truck. I *think* the early 98's used the same system, but, I am not 100% on that. Dodge did even more changes in mid-98, and the cluster changed some more. (electronic prndl, and such.)

So, with the symptoms you are seeing, it appears that the PCM is not communicating properly with the CTM...... which, I would expect would give a "No Bus" error on the cluster. (in the odometer) Are you seeing the No bus??

 

send me a private message for phone to give me a call. Your information is headed in the right direction....