Trailer tail lights not working

Dano218

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Jun 20, 2011
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6
So after my fried ground wire I had I bought a kit to rewire my trailer. Four wire harness and "submersible" tail lights. I spliced for my fender lights red/amber. Those work fine. My center light in the middle of the trailer works fine. My tail lights not so much. Break lights work. Blinkers work but when I push the brakes they stop flashing. They also don't light up when the trucks running lights are turned on, but the fender running lights work. Any ideas? There is no ground wire coming out of the tail lights. Do I need to add one on each light? Help!
 

GA_Boater

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49,038
Re: Trailer tail lights not working

I would run a ground wire from the white wire from the connector to each light, including the marker lights. Relying on the frame for grounding causes just the problem you are describing.
 

limitout

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Re: Trailer tail lights not working

its always a good idea to add a ground wire to the lights mounting bolts but only one is the ground so check you connect to the correct one. you don't need to run it all the way but anywhere there isn't a solid metal like a bolted connection then you should have a wire from one to the other for a solid ground from light to trailer tongue.

all it takes is a little rust or oxidation to cause issues.

also only check the lights with the tongue sitting firmly on the ball because it could be that simple an issue (been there done that lol)
 

GA_Boater

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49,038
Re: Trailer tail lights not working

its always a good idea to add a ground wire to the lights mounting bolts but only one is the ground so check you connect to the correct one. you don't need to run it all the way but anywhere there isn't a solid metal like a bolted connection then you should have a wire from one to the other for a solid ground from light to trailer tongue.

all it takes is a little rust or oxidation to cause issues.

also only check the lights with the tongue sitting firmly on the ball because it could be that simple an issue (been there done that lol)

First - either light mounting stud is the ground for the lights.

Second - the bold highlights exactly why I said to run a ground from the connector. Using the ball as the ground source causes no lights, flickering lights and burned out bulbs.
 

limitout

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Re: Trailer tail lights not working

First - either light mounting stud is the ground for the lights.

depends on the lights you have, not all lights join both mounting bolts to ground which is why I said to check to be sure

the bold is in case they don't have a full wire as most trailers don't, tongue on ball fixing it shows a bad ground connection from plug to trailer tongue or tongue connection to trailer in the case of a tilt trailer.

im not disagreeing with you, a full ground wire from plug to lights is always best, I was just telling him ways to fix his issue the simple way
 

Dano218

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Jun 20, 2011
Messages
6
Re: Trailer tail lights not working

Thanks guys. Lots of good info. All the marking lights I ran a separate ground to the trailer for each. I'll try and run a ground off each taillight and see what happens
 

Dano218

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Joined
Jun 20, 2011
Messages
6
Re: Trailer tail lights not working

I ran a ground off each light and bingo, they are working. You guys are great. Thanks again!
Dan
 
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