How to Replace a 4-Way Trailer Connector with 8 Wires

Updated 11/18/2025 | Published 06/25/2018

Question:

Hello - I am replacing the lights on my Karavan Seadoo trailer. I cut the lamp assemblies off and I wanted to replace the f pinnflat connector as it got road burn. I noticed the kit I ordered comes with new wiring however I was planning on just splicing the tail lights in and connector. The four pin flat I cut off has seven wires and the one it came with has four. Am I able to connect all the whites and all the browns together to make the four wire work with the existing wiring on the trailer? Thank you for your help.

asked by: James

Expert Reply:

A 4-way trailer connector will have four functions which means it will also have four wires for the exception of wishbone harnesses. These four functions are ground, tail light, right turn, and left turn. The ground function will usually be represented with a white wire, the tail light function will usually be represented with a brown wire, the right turn signal will usually be represented with a green wire, and the left turn signal will usually be represented with a yellow wire.

From the looks of the photo you submitted, instead of all the like functions being spliced together and then run to the trailer connector using a single wire, they were all ran to the trailer connector separately. When installing the new lights on your trailer you will want to splice together all like functions and then run a single wire for each function to the trailer connector.

In order to slice the new wires together I recommend using the Deka Heat Shrink Butt Connector part # DW05743-10 as the heat shrink body will work to keep out moisture. I have attached our wiring help article for you as well.

expert reply by: Conner L

click to enlarge

Josh

11/18/2025

Hello! I need to replace the 4-prong trailer connector that has 8 wires going to it. Is there a connector that has 8 stub wires, or can I splice like for like colored wires to a new connect with 4 stub wires? Thanks.

Jameson C.

11/18/2025

@Josh There aren't 4-ways that have 8 wires ran out of them so you would need to pair up the matching circuits per pin and then run them to a 4-way with 4 wires like the part # W787264.

Josh

11/18/2025

@JamesonC all I had to do was connect all 4 brown wires and all 4 white wires, and then green to green, yellow to yellow. Worked fine. Thanks.