Neither my odometer or speedometer will work, They worked after the conversion and when i took it to the shop they said something about the pcm or ecu? They told me that, "this was a common problem with the 12v cummins turbo diesels". Please help me figure this out....?

 

have you checked the speedometer gear?

 

If your truck has the 99 everything but the motor and tranny your problem is the ABS sensor on top of the pumpkin on your rear end. its a common problem on the 1998.5-02 trucks. if you search this in the 24 valve section you will find info on it. the sensor on my 2000 cummins went out twice in the time i had it.

 

no my truck is a 99 but everything was pulled from a 97 Cummins.... speedometer gear? where is that located? would that cause both of the gauges to not work? hopefully this answers your questions and thank you.