There is a thread on here somewhere that has a book with all the wire schematics for our trucks. I believe it was posted by Hook 'em Horns. I tried finding it but, was unsuccessful. I will try again later if I have time. I do remember people saying the book was quite pricey.

 

suzi,
try here. gm shop manuals.
Service Manuals, Owner Manuals, Wiring Diagrams, Service Bulletins - Helm Incorporated

or e-bay- they run about 135-200$

 

Here: http://www.gmupfitter.com/publicat/2004_BB/2003_Beyond_LD_Electric_CK.pdf

 

Here you go. Both fed and cal emissions

 

Thanks a million. Hope I can return the favor sometime.