So I am having the same issues everyone else seems to be having but with a slight variable. I have an 03 trailblazer lt ext and the rear speakers do not work. I did notice the other day that the back left turn on for a short amount of time. So I pulled the speaker today and reconnected it, I found a very minimal amount of water in the door but not enough to ruin a speaker. Also I do have a rear entertainment system but I do not believe it is stock. It's an audiovox screen with dvd player under the seat and it has a toggle switch in dash that runs to some kind off antenna mod that runs to the screen. Please help I can't seem to figure this out.