How to Wire Trailer Running Lamp Circuit w/ Wishbone Wiring Hanress

Question:

my trailer has a green and brown wire that looks like 1pc on the right side and a yellow and brown wire on the left that looks like 1pc and a white wire and my vehicle is made for a 4 wire flat plug with a white wire , green , yellow and brown wire. I did white to white and green to green and yellow to yellow, do I put the 2 brown trailer wires to the brown plug wire.

asked by: Ben

Helpful Expert Reply:

That's exactly what you need to do. Some trailers, especially boat trailers use what's called a wishbone wiring harness where the running light circuit splits into two wires to run down each side of the trailer, one wire will be brown/yellow the other brown/green in color.

Some running lamp circuits will run down one leg of the trailer, and around to the back up to the other side, where it'll stop at the last lamp. Other times, it'll be wired by splitting the single circuit into two, and running down each side of the trailer, picking up each running light and taillight as it goes. I'll link you to our Trailer Wiring FAQ page, which you should find helpful. I'll also link to a video showing a wishbone trailer wring harness being installed.

expert reply by: Mike L