Ok so this is my first post and I don't usually ask for help but I am officially stumped. I have a 08 GMC Acadia with BOSE sound system but no navigation or dvd just good old CD player. I have read many posts and the popular suggestion is that if there is no sound then I have a bad amp. So I purchased a new one of Amazon and replaced it and still I have no sound. I took the radio out and checked the connections and everything appeared to be ok. I do however have sound out of the rear audio jacks if I plug in headphones. Does anyone have any suggestions? I would also appreciate a detailed wiring diagram of the radio, including what color of wires are coming out of the radio and what each one does.