7-Way Trailer Connector Wiring With No Identifying Wire Markings

Updated 04/21/2021 | Published 04/18/2021

Question:

My utility has 7 wires but 4 colors. 3 brown 2 with yellow stripe, 2 yellow, 1 green and 1 black. It was connected to 7 pole that plugged into my truck 7 pole. Wiring got ripped out of pole. I had to by new pole for my utility but it has 7 colors. Not sure how to match. I have not seen a color diagram of wire colors similar/like my utility trailer on the internet. I can get all lights to work but trailer running lights. I can continue to trial and error but becoming time consuming. Have any ideas. Thanks,

asked by: Shawn B

Expert Reply:

I would begin by using a small 12 volt battery to start isolating the wiring. First you will want to trace the wiring to determine which wire is the ground wire. It should be grounded to the frame. Connect the ground to the negative battery terminal.

Begin placing each wire individually to the positive terminal and identifying what each wire operates. Once you have identified the wires I have included a wiring diagram for both the trailer and vehicle sides so that you will be able to use a Circuit Tester # PTW2991 to test the truck circuits as well if you are still having issues.

expert reply by: Bud M