I had trouble with slide in camper when hooked to my TV. TV lights worked.- and finally took it in to have the plug rewired as i had ascertained that was the problem. Was figuring maybe 60 bucks if I was lucky.
They called. It was a fuse.
Felt pretty stupid.... but I had never really looked into what was what on tow vehicle and didn't realize the factory wiring was in fuse bank in engine compartment. Live and learn.