02 envoy radio issue

My radio is working intermittently. When it works, I only get full sound from left side speakers. Right front is not full sound and right rear doesn't work at all. Also noticed that when it is not working that the alert that keys have been left in ignition when car door is opened does not sound. Any one have a clue what could be causing this? Only owned this envoy since july 07 and beginning to think I mad a bad choice!

I am having the same issue. Any help would be appreciated.

I'm having the same problem! and the dealership wants $85 just to diagnosis it!