Trailer Lights Issues

When I went to get my boat from the in-laws last week, they said the trailer lights didn't work and they had "tried everything." They stuck a set of those magnetic lights on the rear of the boat and ran the plug up to the truck and that got it home ok. I checked it out the other day, the ground is good. No broken wires from plug back to lights. Haven't checked for continuity with my voltmeter, but I got the lights to work somewhat, so there is voltage there at least. The problem is, the right turn signal will not flash if the headlights are on. With the head lights on, it is much brighter than the left one and won't flash, but with the headlights off, it is the same brightness and flashes fine.

When I first checked it out, they had the wires all crazy. Each light has two wires, on one of them they had both wires going to the same wire from the plug/harness, and on the other side one wasn't hooked up at all, I think. It's hard to explain how I have it without a diagram, but each wire from each light tells exactly where it should go. It is wired exactly like it says, green to green, green/brown to green/brown, yellow to yellow, yellow/brown to yellow brown, etc.

The only thing I can think, my mother in law said they changed one of the bulbs trying to get it to work, I wondered at first if it was the wrong style, but it is the same as the side which works correctly. I'm not sure if that would make any difference, anyhow. Could it be a vehicle wiring issue? I don't have a truck, so I have to borrow my dad's to go fishing and he has never pulled a trailer so he doesn't know if it has worked ok with other trailers.

Thanks for any ideas!

I'm not an expert by any stretch, but almost every problem I've had with trailer lights has been a ground issue and maybe also water getting into supposedly sealed lights.

A few years ago I ran a dedicated ground wire to each light back from the front of the trailer and also replaced all lights with leds. Have not had any problems since. Good luck.

I agree with crappiewisdom you probably have a ground problem. I don't understand the green/brown wires. The green goes to the right light and serves as the brake and right turn light while the yellow does the same thing for the left. The brown splits and goes to both lights and will be on when your vehicle lights are on. The white is the ground and grounds to the trailer frame. The lights ground to the frame where they are bolted and thus should have continuity to the white ground. The problem with grounds could be where the lights are bolted to the frame or if you have a tilt trailer the tilt pin will get rusty and you will loose the ground. The trailer will ground through the ball without the white wire but you will have to drive around for a while to get rid of the bad connection (rusty ball) Hope this helps.

buy a trailer wiring kit and do the whole thing over, that way everything will be new and in good condition. sounds like too much jury rigging and somewhere there are crossed wires.

Quote:

---

Originally Posted by wannabe fisherman

buy a trailer wiring kit and do the whole thing over, that way everything will be new and in good condition. sounds like too much jury rigging and somewhere there are crossed wires.

---

X2 Get new lights and wires in a kit. You will save your self a lot of grief that way.

Get the waterproof ones if you can.

theysaid