Utility Trailer Wiring Harness. Most boat trailers and small utility trailers that don't have their own brakes use this kind of harness plug, often referred. I installed the trailer wiring harness today, WHEW, what a job!
All right, now with everything hooked up, we can use our heat gun to heat up our heat shrink. Video tutorial on how to wire trailer lights. I had to replace old wiring harness on truck for utility trailer.
We went ahead and just wrapped everything up with some electrical tape just to provide a little extra.
So here I have an older trailer which needed some work, along with re-wiring the lights.
When I towed a small utility trailer, it worked beautifully. I did originally order the wiring from trailer so once i get the OEM I can compare and return the one I am not using. The last wire of a standard four-wire system is white -- it's used as the ground wire.