To start off I have a Pioneer double din with the stock speakers and some subs. Everything has been working good for the last couple years. I drove the truck today and it was fine. I came home and went to go leave again and when the deck turned on it was just subs. Everything on the deck seems to be working fine. I noticed when the deck turns on the rear right speaker will crackle but no other ones will. Any tips on where I should start looking. Iv tried resting the deck by pulled battery negative but that didn't work and it got dark. Maybe for some reason I got a bad connection in the back or maybe the deck is just toast. any help will be appreciated.

 

I would start by pulling the unit and testing it on the bench. if it works then I would check the resistance of each speaker channel in the truck. if you don't find anything abnormal then I would connect each channel in the truck one at a time.

If the unit does not work on the bench then you would need to replace it, fix the internal amp or run a external amp off of the rcas.