How To Rewire A Trailer Side 7-Way Socket After It Gets Ripped Off

Question:

I have a horse trailer, a Heartland all aluminum. Owner pulled the socket out of the truck plug by driving ahead after he disconnected from the trailer without unplugging from the truck. All his wires pulled apart from the trailer connector when rewiring found out he has a hot wire red line coming from the trailer that is live. And the black thats supposed to be to the hot for battery isnt. He also has lights that do not function on the tailend if the black is hooked up, and i cant hook a hot line to the plug from the trailer to the plug because we will short something out any ideas

asked by: Craig S

Expert Reply:

If all of the functions were properly working before the 7-way socket was yanked off of the cable and now they aren't working then the socket has been incorrectly rewired or the wires were yanked out in the junction box causing a loss of connection to the trailer wiring. Wire colors varying so much that you can't trust the colors to determine what the function is and will have to put power to the wires to actually determine their function.

If you have the trailer battery nearby you can run a jumper wire over from the positive terminal on the battery and touch each wire in the junction box separately to determine the wire's function. Once you know which each wire does you can then follow the guide below to rewire the cable into the socket. I've attached a diagram below that shows the pin functions from both the front of the socket as well as the backside so that it's easier for you to rewire it.

If you have any more questions please feel free to submit another question via our 'Ask The Expert' link and I'd be happy to keep troubleshooting with you.

expert reply by: Kevin C