I just ordered a complete kit for 45$ lets see next week if it works . The problem im having now is that the factory Xm module needs a class 2 data connection that runs under the steering wheel harness splice pack 206 and i can see that connection Being available for me to run a wire to the module. I have 2 modules a 2003 and a newer one 2006 from another hummer . I thinks thats the cable that other than tech2 diagnostics i think its the way the truck actually sees the module the only other cables that run to the radio from the module are audio left audio right and audio common . Battery power and than the class 2 data cable .

 

the class 2 buss is part of the radio "T" harness the module connects to. look at the pdf i posted for the module i posted above.