Why Would Trailer 4-Way have 7 Wires Ran to It

Question:

I have a boat trailer with 7 wires feeding into a standard 4 flat male plug. The pug and wires are all molded together so it was factory Wesbar. Appears to be two white ground wires. All the other wires are various colors. Why all the wires? I need to replace the first few feet.

asked by: Glyn T

Expert Reply:

Since wiring runs to both sides of the trailer sometimes we find that trailer wiring will have a left and right hand side for each relevant circuit. Sometimes also there are multiple ground wires as well. Normal circuits that are split for each side is the ground circuit and the running light circuit. Which leaves normally two wires left. One for the right hand stop/turn circuit and one for the left hand stop/turn circuit. That's a total of 6 so a 7th wire is probably an additional ground. But I would have to look at the connector. You can also trace the wiring of the connectors to try and find where they terminate as well.

expert reply by: Jameson C