Installation of 7-Way Trailer Wiring When Colors Dont Match

Updated 01/14/2019 | Published 01/12/2019

Question:

Since the wire colors on the HM20087 dont match the colors on my trailer I am not 100 positive that I have them connected correctly. If I have connected the wires incorrectly am I going to cause any damage or will it just not work correctly?

asked by: Robert T

Expert Reply:

If you have connected your Hopkins 7-Way RV Style Connector w/ Molded Cable and LED Test Lights - Trailer End - 8' Long # HM20087 incorrectly, you will not cause any damage to your system as long as the ground connection installed correctly. If the ground is in the wrong location you have the potential to blow fuses, damage lights, etc. If the ground is in the correct location, then the wiring will work and you just will need to match functions.

If you are unsure of the ground connection, I recommend testing your trailer functions with a 12V battery with a 12v power wire and the negative terminal of the battery being connected to the trailer frame for your ground. Then you can match the light and brake functions to your trailer based on the wiring function colors of your new 7-way harness. The wiring configuration is:

White: ground wire
Red: left turn/brake light
Brown: right turn/brake light
Green: tail lights
Yellow: reverse lights
Blue: electric brakes
Black: auxiliary power

I've attached an article on wiring to further assist.