Probably shorted trailer wiring took out both the trailer tail lights and the camper tail lights. I found and removed an exposed wire. But I can't get the tail lights back. The tail lights on the...
Yeah I think I'm making progress. The trailer takes power from a separate family of "trailer fuses". The camper draws it's power from that same trailer wiring.
So if the trailer blows a trailer tail-light fuse, both the trailer and camper will lose the lights. But not the truck. I think I found the bad fuse, but it's a weird shape and I have no spares. Off to the auto parts store.