I have a 2006 sierra 1500 sle crew cab. It has a radio with single CD player. The sound level and quality is very poor. At full volume, the sound is very low and the sound quality is very poor. This problem developed within the last few months. Occasionally, the sound in one of the rear door speakers will be good (usually in warmer weather) but now it is rarely good. My GMC dealer wants over $600 to replace the radio/cd player unit with a remanufactured unit. I would appreciate any advice regarding the likely nature of the problem and, if replacement is the best solution, advice regarding a do-it-yourself replacement.
