Check out the following site and it will explain more in detail .I have spoken direct to John and he will help you in anyway possible
http://www.speartech.com/
I was going to have Speartech rework my harness until I purchased the following from this site http://www.currentperformance.com/eng_mgt.html#Mod
it should get the system up and running .It includes diagrams and marked wireing connections with relays and fuses.Pretty sweet and cheaper than the rework if you understand basic wiring.Feel free to drop me a PM if I can help.

Last edited by 61 suburban; 04/01/2008 1:41 AM. Reason: spearteck link didn't come up
In the works 2006 GEN III 6.0 /4L80E/ 205 New process,A/C and power brakes .