Replacing Damaged 7-Way on Horse Trailer

Question:

I have an 2 horse sundance trailer I have to replace the 7 way plug on as it was ripped out. However my wiring does not match diagrams. I have Brown, Yellow, Green, Red, Black, Blue and white wires. How do I wire the new plug?

asked by: Mike B

Expert Reply:

There's more than one accepted way to wire a 7-way, but the most common uses the green wire for right turn/brake, yellow wire for left turn/brake, brown for running lamps, blue for brake output black for 12-volt accessory power to the trailer, white for ground and purple for the reverse light circuit.

Because wire colors can vary so greatly, we typically tell folks to wire by function, not by color. An alternative color code is yellow wire for auxiliary or reverse lights, green for running lights, red for left turn/brake, white for ground, blue for brake output, brown for right turn/brake and black for 12-volt accessory power.

The best way to confirm which wire serves which function is to use a car battery to apply power to each circuit. I've linked you to our trailer wiring FAQ article that shows the two most common ways to wire a 7-way trailer connector.

expert reply by: Mike L