I installed a new deck and speakers about two years ago in my 2002 Explorer. A couple of months ago, my daughter who sits in the back seat said her speaker was crackling. After doing a quick test, I found that there is no sound coming out of it, but a little crackling and also the other rear speaker was not working at all. Due to the cold weather, I have delayed this project. Should I start at taking out the deck and looking at it, or should I check the wiring in the doors? I am leaning towards checking the wiring in the doors.