I recently bought a used RV and it had a Sony CDX-GT400 / XPLOD XM-554ZR stereo system installed in it. I cannot seem to get the speakers to change locations in the RV, at this point the only speakers that have sound coming out of them are the outside speakers and I want to know how to change locations of the speakers. I even called Sony and they could not help me, so I hope someone in cyberspace can help.