Replacement Wishbone Style 4-Way Trailer End Plug

Question:

My 4 pin plug coming off of my boat trailer has five wires. Two of the wirea yellow. I can not find a plug that has 2 yellow wires to replace it.

asked by: David E

Expert Reply:

Thanks for that photo and what you have is a wishbone style wiring harness, although the colors are inconsequential for a harness because there isn't a standard wiring code that is color-for-color. You can replace your harness with the Wesbar Wishbone Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End # 002402 but you will need to wire it by function.

This means you'll have to apply 12 volts to your wires via a battery to determine the function of the wires so you can connect the new trailer plug. Or you can try and trace the wires back to determine the function of each, though this can be pretty tricky.

I have added a link to a video review of the Wesbar Wiring Harness for you as well as a link to a help article on trailer wiring which I highly recommend taking a look at.