Junction Box and Connector for Trailer Wiring

Updated 07/05/2021 | Published 06/28/2021

Question:

I use a seven pin plug but only use six wires brown blue green yellow white and red I have tried several different ways I think green is trailer breaks the white and red wire are a bigger gauge

asked by: Brett O

Expert Reply:

I have attached a diagram of the standard 7-way wiring hook up for 5th wheel, travel trailers, and campers. This should help you to identify which wires should be running what function on your trailer.

To be completely sure which wire is which you'll need to test each circuit to identify their individual functions. You'll need to use a power source, like a car battery then put the ground to the negative and each of the other wires to the positive one by one. Whatever function activates on the trailer is for that circuit.

I recommend using a junction box once you've identified the wiring functions on your trailer. The junction box item # HS381-9000 would be perfect for this and also comes with a 5' 7 way connector.

expert reply by: Jerred H