Wiring systems

Larry, go to google.com an type in your wiring diagram. It will show you pictures an it will tell you step for step how to do it. Good luck.

First, make sure you use every possible control from the 2012 and refit the '12s instrument cluster into the '03s dash its a must.. try and keep the '12s wiring intact as much as possible, modify the '03s cab and chassis to accept the '12s wiring and accessories. That will help reduce some of the work even so you're going to be doing a lot of work reading schematics and tracing circuits. This is more work than adapting a crate engine to factory fuel injection without a harness! all hand designed and fabricated. It can be done just lots of hours and concentration. Make sure to record and keep a "PATTERN" of wire colors and lengths, changes and splices etc.. You could probably market it when your done!! Regards