What could be the source of the problem? I have a Pioneer DVD/monitor headunit that connects to an audio/visual master unit in the trunk. Here are some key points that may help someone narrow the problem down. --I disconnected all of the cables (one at a time) that connect between the two and each time the system shuts off so I'm assuming that the cables are good. --My amp for the sub connects straight to the audio/visual master unit via RCA cables and it works fine. --My door speakers that dont work are connected to the a/v master unit with no type of amp. --I tried to connect a different set of speakers to the existing subwoofer amp and still no sound but the sub is still bumping. --The setup I have worked for two years with no issues. The sound went away in a day but was intermittant on a bumpy road a few days ago. Anyone have any ideas? I am leaving for the middle east in a few days and would hate to leave my wife and kids with no tunes for a few months.