SIR-GM1 Issues with 04 Tahoe

I have a 2004 Tahoe with the Tough Screen Nav, and the Denali 6 Cd Changer installed. Non XM truck. Everything workes perfect, I just added a SIR-GM1 Sirius unit to the truck and when listeneing to the CH changer i get alternator wine thru the speakers, take out the SIR and its perfectly qiet playing the CD Changer thru the NAV. the rear audio controls also do no function properly when listening to the Sir-GM1.
It also accasionally will play the sirius and the CD at the same time when the truck is first turned on, any guesses or any one have the same issue?

Im going to direct wire the SIR-GM1 into the truck just as the Stock XM is wired into the truck. I will let you knwo the results