Does anyone know if there's an adaptor to match the end plug coming from the engine compartment through the firewall and connecting to the dash (ignition) harness, when the engine harness (computer module) is for a 2002 cummins 24 valve and the dash connector is a 95 3500 older 12 valve cummins engine. "Puzzeled" !!!

 

I would seriously doubt it. The older 12 valve motor is almost completly mechanically controlled, very little computer interferance. The modern 24 is almost all computer controlled. It is very unlikely you can mate the two together without the complete harness and computer that that 2002 motor came from. Good luck.

 

I kinda agree with the above statement but, if any place has what you're looking for... it'd be here http://www.painlessperformance.com/
I'd call them to ask about what you're looking to do.

 

Thanks for the great advise, I've talked to a few with similar endeavors and learned that the inside (cab) module and harness will most likely have to be switched out with one from a 2002.
Still sketchy as to what essential systems for the new engine and tranny apply, other than the speedometer to make the trans. shift properly. I have installed the underhood wiring harness and computer with only minor glitches, just not sure of dash intrument relationship with the new computer.