Mine too was wired incorrectly on my TQ 365. The balance would change inside to outside speakers, so we had Right in the Living Room, and Left Channel outside. Good thing I did not try to play anything from The Who!
A quick swap of some wires fixed it and now the fader controls inside/outside. I also piped in the DirecTV receiver into the rear aux inputs to make up for the horrid TV speakers. I'm finding a lot of little stuff here and there, but none of it's worth hauling the trailer back to the dealer to fix.