I have a 1982 hi-lo just bought used. I know very little about rv's this is my first one. When the rv is hooked to it's battery everything seems to work as it should. When I connect the trailer plug to my truck the reverse lights come one. if I disconnect the trailer battery they go off. this only happens when it's plugged to my truck through the trailer light connection. Any suggestions on getting the reverse lights off without having to disconnect the trailer battery?

ps. i checked the wiring at the plug and it all appears to be in order.

thanks
Curt

I would unwrap the wiring and disc the one wires that powers the light that youwant off. Google trailer plug wiring and with the diagram isolate the wires then disconnect .

You may have a junction block in your battery box where the pig tail to the female plug of the trailer connects the wires.

Put 12 v power to the plug via a jumper wire from the pig tail to the proper connector to test.

I have seen parked campers with their running lights on at night and wondered how the did that. Just a simple jumper wiredoes it.

Thanks for the reply. I had isolated the wire, it's the yellow 16gauge wire that is supposed to be for the backup lamps. checked the continuity from front to back and all was fine there too. Pigtail and plug are both wired correctly (checked them both, truck and trailer). It just seems like there is something that switches over when you connect the power from the truck to the trailer. as far as I can see the backup wire is straight from the pigtail to the backup lamps. Seems there is really no reason for it to connect to anything else. guess I'm going to disconnect the backup lights on the trailer.

Some 7-pin configurations switch reverse and 12V wires, it could be the 12v from the vehicle is in the opposite location of that on the trailer. The other thing it can be used for is running lights at which point its going to be on when plugged in. Hope that helps, i'd check the normal 12V pin out and see if power exists there to make sure they aren't reversed on the vehicle.