I have a 1997 Chevy Blazer (4 door). My radio works, and the speakers in the front of the car work just fine; but my c.d. player will not play any c.d's and my rear speakers make no sound. I also have trouble with my back window wiper, it works once every 6 months for about 1 minute. Very frustrating given that I live in Washington. Any clue if my problem is a power shortage to the rear or if it's the speakers? It'd be a pain to take the door apart and check the speaker so I'm hoping there's an easier way. Thanks!