Hi I just bought a 02 trailblazer Ltd and it has a aftermarket stereo in it. The rear stereo controls and speakers are not working. I was wondering if this was because Of the aftermarket radio. I was thinking of putting a stock radio back in if this is the problem. The codes show I have a cd and cassette deck stock. I was wondering if I could just get the cd radio or the 6 disc Of if I need to have bose amp and stuff to work. I would just rather not have the cassette deck part. Thanks for the help