I have a 2005 GMC 1500 with a Bose system and OnStar. I have installed a double din JVC head unit only. I used the RP5-GM11 interface module with the chime module and steering wheel controls etc. Everything seems to work as far as steering wheel controls, the radio picks up the stations etc. but there is no sound. Now if I turn OnStar on and off the sound will come on and work fine. Everything works fine but as soon as the truck is shut off I have to do that again to get sound. Like I say the stereo is not losing power as it keeps the stations memorized and the clock is ok etc. but every time I start it I have to bump the OnStar on and off to get the sound going? Any thoughts would be great thanks.