How to Splice in Replacement 4-Way Trailer End Connector

Published 05/07/2019

Question:

I need to replace the trailer connector. I have a 4 pin replacement and it has a green, yellow, white, and brown. The damaged plug on the trailer harness has a white, yellow, yellow- brown, and yellow-green. All the videos and diagrams mention a 5 pin or there is a green or a brown wire. I only have yellow wire and 2 other wires that are yellow with green and yellow with brown. Do I splice it in matching the wiring on the plug meaning yellow to yellow, green to YG, brown to YB, of course ground is white. Wasnt sure.

asked by: Jack S

Expert Reply:

To splice in a trailer end connector such as the 4-Pole Trailer End Connector # 18004 or Hopkins Endurance Easy-Pull Harness w/ 4-Pole Flat Connector - Trailer End # HM38134 you will need to match the connector to your wires by function. On these connectors, the brown wire is the tail lights, the green is right turn/brake light, the yellow is left turn/brake light and the white is ground and your connector will likely be the same.

Since your damaged plug does not have these you can either trace the wires on your old connector to their function (tail, turn signal, brake light, ground) label them as such so you know what is what, or use a 12 volt battery and jumper wire, applying 12 volts to the wires to see what gets illuminated so you know their function.

I have added a link to a help article on trailer wiring for you that I highly recommend looking at.

expert reply by: Kyle S