take out you deak and check your wiring to make sure you power and acc havent came loose, also check that you speaker leads are still connected and not tuching eachother. also your cig lighter has a clip on the back of it take your pannel off and check to make sure it is still connected, if it is still connected pick up a used one at a local junkyark and replace it there not expensive

Do you have any dimming of you headlights or other lights in or out of your car?

also did your deck and your light stop at the same time?