mx6.com has helped me out a lot in the past. This is for a SC-901 volvo head-unit. All of the speakers except one in the car are powered by a 4ch amp. Everything works fine for about 20-30 minutes. After that time, all of the speakers besides the one cut out and stop working. After that, those same speakers turn on and back off with about 3-5 minutes each way. Is it the amp going bad? Wiring off somewhere? or could the head-unit itself be not sending the signal to the amp? All help appreciated. Karma to those that help out the most.