Hello everyone im recently started to try and add xm to my 2004 hummer h2 that did not come from factory equipped Xm receiver . I got a used SIR-gm1 receiver with the proper harness for my truck . As far as the antenna im using a GM antenna that has the same connection. My current situation is that i can see the Xm channels xm1 and 2 in my radio but no radio id or preview channel on 184 comes on . I went ahead and called xm and added service to this unit thinking this may off help and also tryed tech support but had to hang up because honestly the lady did not have a clue of what she was doing. I followed the installation instructions to the T with no luck. If you have one of this units and have depth knowledge please let me know. Thanks in advance.