Can a Red Wire be a Ground Wire in a 7-Way Trailer Connector

Updated 09/01/2016 | Published 08/31/2016

Question:

I used this diagram for my horse trailer 1:00 is Black and 12 volt power 3:00 is Green and Right Turn and Brake 5:00 is Blue and Brake Controller 7:00 is White and Ground 9:00 is Yellow and Left Turn and Brake 11:00 is Brown and Tail and Running Lights Center is Purple and is Optional Reverse everything works good except I have dont have a white wire for the ground the only wire I have left is a red wire and Im not sure if it would be the ground or not

asked by: Jake S

Expert Reply:

By process of elimination the red wire must be the ground. But while there are common wire colors used there isn't a standard so the red wire could technically serve any function (except that you noted that everything works).

On a 7-Way the only circuit that won't have power at some point would be the ground. So if all the other wires show power when a function is on and that red wire doesn't then it has to be the ground. But it must already be grounded somewhere because if it wasn't then the circuits would not work properly or at all when a trailer is connected.

expert reply by: Michael H