I have a 12 Avalanche. The rear stereo speakers work intermittently. The front work all the time. On the rear, sometimes one comes on, sometimes both come on. Most of the time, neither are on. I cannot figure out what causes one or both to suddenly turn on. They might stay on for 10 minutes, or an hour or anytime. And the fader is in the middle. I turn it to the rear and when they’re not working, there is no sound at all. I have searched the threads and not found an answer. I’m sure I’m not the only one who’s had this issue.