Ours is like Ron's. One on either side of the gaucho up front and one on either wall in the mid bedroom area. When I removed the interior walls in mine, there were several 12v
DC wires coiled up in the wall, apparently to be used for optional lights and so forth. I'll bet that's where they are.
One possible way to find them is to take the inner ceiling skin out. IT"S A LOT OF WORK! But all of the wiring runs down the center of the trailer ceiling, and then branches down the sides to the outlets, lights, speakers and so on.
Good luck with it, maybe somebody will have an exact answer for you.