Troubleshooting Install of Wishbone 4-Way Where Left Blinker Doesn't Work

Question:

Hello! I accidentally ordered a wishbone style harness for my vintage trailer. The trailer only has 4 wires. I understand what the wishbone harness is for, so you dont have to run a jump wire between the tail lights. However, I am in a hurry and dont want to reorder a new harness. If I wanted to hook up my wishbone harness on a trailer that only has the four standard wires...what do I do with the extra brown wire that splits off from the green wire? I have hooked it up once with both brown wires from the harness connecting into the single brown wire on my trailer, all other wires are color to color. Running lights and brake lights work, but no matter whether I signal to turn left or right, the right blinker is the one that blinks. The left doesnt blink. Should I give up and order the standard 4 way flat harness and start over, or is there a way to use this wishbone harness that I already have? Thanks for your time!

asked by: Mary

Expert Reply:

Wishbone running light circuits can easily be used with standard trailer 4-way wiring setups. All you have to do is run the two wires on one side together in a butt connector and then attach it to the single wire on the trailer. It sounds like that is how you intended to wire you trailer but I believe you have a couple wires mixed up.

From the picture you submitted it looks like you have everything wired up properly as all of the colors match properly. But as I looked up further on the wiring in the picture you send it looks like the brown wire is connected to a green wire and a few other colors are mixed up.

The best advice I can give is to use a jumper wire to apply voltage to each of the pins on the trailer's 4-way and see which trailer taillights come on and then correct as needed. Or you can trace each wire to see where it goes.

expert reply by: Jameson C