I am changing out my factory radio to put in the navigation one. I purchased model number 15800000 and it works great I had i unlocked and all is good. When I purchased my radio the guy sent me the xm module as well. What I would like to know is where does the xm connect? There is not a harness in back of the radio to connect it. If someone could send me a pic of where in the tahoe it goes and if possible the clip that goes in it. Hopefully I could buy the back piece.. Thanks in advanced.