I have a switch located on the left side of the factory TV cabinet that allows me to play the dash radio through the surround speakers. When it is in the dash radio mode the speakers, including subwoofer, all work fine. When I switch it to the AV side, the surround sound doesn't work properly. I never realized this until yesterday when I was pulling out the components to upgrade the TV. The center speaker and sub wasn't working at all. I haven't been able to locate where the 2 wires go (From the switch) that makes the dash radio play over the speakers. Is anybody familiar with this?