I have had a wire harness made for my 2004 K2500 HD Transfercase so that I could plug it into my truck along with the 6.0 and 4l80e. I have wire diagrams for a 2004 cheverolet chevy K silverado 4wd. The problem is that the wire harness was originally built for a the 1/2 ton shift control module rather than the heavy duty one. I am told that the only difference between the two in the speed sensors on the T case.

Is this True?

Also, the bigger problem is that I am not getting the shift control module to "power up" so nothing seems to work. I have ground and 12 volt reference but for the loop that activates the shift control module I have no power, or five volt reference. The only wire that I can see that is out of place is one purple and white wire that lights up the control switch, according to my diagram it should is in the right place but when I manually test it the wire should be moved over one place. Does anyone know where or how the control module gets power so I can get this thing to work?

I do not have the schematics for data link communications, is there any chance this is what turns the loop on? There is one wire that goes to the PCM and as near as I can tell it is in the right place.

Sorry for all the details, but I am praying someone knows how to help me!

Thanks