Diagram to Use When Wiring 7-way in Place of 6-Way on Horse Trailer

Updated 09/09/2019 | Published 09/06/2019

Question:

Hello, Im rewiring the plug to my horse trailer. There are 6 wires coming out of trailer : green, black, yellow, red, blue, brown. The original plug head was 7 way with nothing plugged into the center and blue attached to nothing, just cut back. The screws were marked with colors and were wired accordingly. The new plug just has labels like Auxiliary, Left turn, right turn, ground, etc Hopkins 7 blade #48505. The trailer has breaks and an emergency trailer breakaway. There is a 12V battery on trailer as well. I have no idea where to put the wires. My truck doesnt have a trailer break controller installed yet but I will be installing shortly. How can I figure this out?

asked by: Sydnye W

Expert Reply:

Your best option is going to be to use the wiring diagram I attached for 6-ways to identify the functions of the wires from the picture you sent in and then wire them according to the labelled pins on the new 7-way similar to the # HM48502 and you'd be set. Use the set screw that you see in your picture as the "top" when comparing what you have to the wiring diagram.

The center pin is the 12 volt circuit on the 6-way and if you have no use for it (it has nothing to do with brake controller) you can leave it off as well when installing the 7-way.

expert reply by: Jameson C