Determining Wire Functions On A Trailer To Install A 7-Pin Trailer Connector

Question:

I have a trailer wiring setup and the builders have used 2 lengths of 4 wires. Each has red, black, white, and green wires. Can you offer a solution for that to a 7 pin plug

asked by: John T

Expert Reply:

The first thing you need to do is put power to the wires to determine what their function is. You can use some spare wire to connect a 12v trailer battery directly to the wires in question and see what lights come one to determine their function. From there I recommend installing a junction box and 7-way cable, like part # e99011, in order to organize all your wiring and give your trailer a 7-pin trailer connector.

I've attached a video below as well as a help article to help walk you through this process.

expert reply by: Kevin C