2005 silverado radio wiring

i need to find out the wiring for a 2005 silverado radio. i'm trying to hook up a xm radio unit and i want it to turn off with the radio. any help would be great

You are going to have to tap into a switched 12 volt wire. You can use a fuse tap in your fuse box or you can tap a wire in the ignition harness. You won't find one behind the radio because this truck is equipped with the class 2 data bus system. Make sure to fuse the wire you use to tap into the switched power source.