How To Wire a 7-Way Trailer Plug To A Vehicle With 6 Wires

Updated 07/02/2019 | Published 07/01/2019

Question:

I am trying to wire but color code doesnt work because there are no red and blue wire only two brown wires. I cant get it to even show power now, if I wire correctly by the four colors that I can follow. The two brown wires are the problem.

asked by: Robin

Expert Reply:

I am not sure which side you are referring to, the vehicle or trailer but regardless you will need to test the wires for function instead of color matching. In order to do this on the trailer side you will need to apply 12 volt power to each wire and see which light it illuminates. In order to do this for the vehicle side you will need test each wire with a circuit tester while applying the respective signals in the tow vehicle.

If you are installing a trailer side 7-way trailer connector then the missing wire is most likely for the reverse light circuit which will not be ran if reverse lights are not present on the trailer. When installing a 7-way trailer connector, I always recommend using a junction box like the one in the Trailer Wiring 7-Way Upgrade Kit part # HS381-9000 as it not only looks betters but also helps with troubleshooting.

expert reply by: Conner L