Tom-
Do the camper lights run off taps into the light circuits on the truck, or do they connect to the trailer tow harness/package installed by the factory for the towed vehicle?
And how are the trailer lights tied into this? Into the factory trailer tow harness or to the lights on the camper?
How are the camper and trailer grounded? Just through contact of the metal bodies, or are there positive connections through wire connections everywhere?
Are all the pin connections intact in the plugs, and are all the wires connectded to the right pins (instead of a brake wire connected to a back up light circuit, for instance.)
You (or me at least) usually need a continuity tester and a digital volt/ohm/ammeter to track down this kind of problem unless visual inspection shows up some glaring error.
Of course, there always some crazy possibilities, like someone having connected the camper and trailer lights in series rather than parallel, but there are a lot of strange possibilities behind those kinds of doors.
One thing that sometimes happens is that a poorly grounded brake/turn light bulb in corroded socket will run current back through the tail light filament in the same bulb and wind up lighting it up and the tailing light bulb on the other side, and even perhaps the side marker lights, which are on the same circuit.
Things can get weird in a hurry!
Guessing about this is difficult to the degree that I don't have physical access to all of the information and the ability to test out each circuit for correct or possibility erroneous circuitry/connections.
Joe. :teeth :thup
