tail light problem

[josumama]

I cannot get my left tail light on my trailer to function. The right tail light works fine when turning or braking. I had a damaged car to trailer connector, thought that was it. It wasn't the problem. I replaced the bulbs. Still the same. I checked all of the wiring, seems to be intact. I connected the tail light assemble to some batteries and it lit up. I can't figure out what is wrong. Please help, suppose to be taking the boat on vacation in 2 days!

 

[boat1010]

Re: tail light problem

Usually the problem with trailer lighting is the ground. You need to check all the connections, take them apart and clean the connections.

 

[Juror81]

Re: tail light problem

I cannot get my left tail light on my trailer to function. The right tail light works fine when turning or braking. I had a damaged car to trailer connector, thought that was it. It wasn't the problem. I replaced the bulbs. Still the same. I checked all of the wiring, seems to be intact. I connected the tail light assemble to some batteries and it lit up. I can't figure out what is wrong. Please help, suppose to be taking the boat on vacation in 2 days!

Check the ground. I had similiar experience that you described and the ground on the left light is the culprit. Make sure to unplug your wire harness when you lower the boat.

 

[Bob's Garage]

Re: tail light problem

Your tow vehicle may have separate fuses for the trailer harness. Did you check the vehicle end of the connection to verify that you are sending current to the trailer? Test plugs are available and cheap. Fuses are probably located under the hood.

 

[Trooper583]

Re: tail light problem

Yep, the ground...a bad ground can make those things do weird things. dim burning bulbs, not working period, etc. I would say that your ground wire on your fixture is probably grounded directly to the frame as most of them are. Go to the hardware store and get a washer that has the teeth on it. When you tighten down the grounding screw, the teeth on the washer will penetrate the paint and go straight to the metal of the frame. If you want to go one step further, lightly sand the paint off the trailer where the ground screw goes in.

 

[109jb]

Re: tail light problem

Most trailer light systems use the trailer frame for the ground. I don't like doing it for trailers. I think it is especially dumb for the manufacturers to do this on a boat trailer. All of my trailers (boat and otherwise) have dedicated ground wires for the lights that go from the light all the way to the trailer connector.

 

[josumama]

Re: tail light problem

Thank you everyone. It sounds like the consensus is the ground, an easy fix. My son, the former high-school car rewiring specialist, agreed with your assessments when he called after work last night.

 

[sublauxation]

Re: tail light problem

I'm going wit Bob on this one. Check the fuses for the tow vehicle, many have separate fuses for each side trailer lights. Do you have power at the plug on the vehicle for the left side?