Trailer lights

[Fishhunter38]

Not a motor question, but not sure where to ask it.<br />I recently picked up a smaller boat and trailer and need to change out the lights. Well went to Walmart and got a set of trailer lights and installed them. Pretty simple I thought a no brainer.<br />Well the problem is that all the lights work running, right signal, left signal except when you hit the brake all the lights go out.<br />Checked (with tester) the truck plug even tried the neigbors truck and same thing. <br />The new ground seems good. Any help would be appreciated. Thanks

 

[JB]

Re: Trailer lights

Hi, Mike.<br /><br />Welcome to iboats. <br /><br />The correct forum for your question is Trailers.<br /><br />I will move this there.

 

[cp]

Re: Trailer lights

Check ground connection between each light and trailer frame; most likely bad there. Use star washers on connections; make sure teeth penetrate through any paint to bare metal. Good luck.

 

[Fishhunter38]

Re: Trailer lights

There is no ground between the lights. It was just a simple trailer light package. I attached the ground provided at the trailer plug with a self-tapper in a pre-drilled hole.

 

[Fishhunter38]

Re: Trailer lights

If the ground was bad won't the lights not work at all

 

[jajeeper]

Re: Trailer lights

Incorrect. Trailer light problems like this are almost always grounding problems. Each light is ground to the trailer by the bolts that hold the light on. As stated before, make sure the nuts used to hold the lights are are making good contact with bare metal on the trailer. You may have to sand the paint away slightly where the nut tightens against the trailer.

 

[Fishhunter38]

Re: Trailer lights

I forgot to mention it is a tilt trailer. Should I try and extend the ground beyond the tilt portion of the trailer.

 

[jajeeper]

Re: Trailer lights

Nah...your ground wire from the plug will be somewhere near the tongue of the trailer and each light will be grounded by their mounting hardware. That will be sufficient.

 

[WSUDERMAN]

Re: Trailer lights

The trailer lights should have two wires. One is for running lights and turn signals. The other is for the brake lights. The grounding should be through the light housing/mounting. The bulbs should have two elements in it, make sure both are good. <br /><br />To help isolate the problem try directly hooking the light to the truck plug. don't forget to hook the mounting location to the ground wire.

 

[cp]

Re: Trailer lights

Sorry, guess I wasn't clear enough when I said<br />

Check ground connection between each light and trailer frame

I meant the ground from each light to the trailer frame, not between lights.<br /><br />Mike64 - the trailer running lights can work in the absence of a good ground at the trailer lights because the current will flow through the vehicle's brake/turn filaments back to the vehicle ground. (The brake/turn lights don't light up then because the voltage is dropped across the higher resistance of the running light filaments.) But when the vehicle brake filaments are energized the voltage applied keeps the trailer light current from flowing through the vehicle brake filaments and all the trailer lights go out. You've got those classic symptoms. If this is all Greek to you, don't worry about how it works, just go make sure each light has a good ground to the trailer frame, like jajeeper said in his first post above.<br /><br />As 78FOURWINNS says, if you've only got 2 wires coming out of the light, the ground is likely the mounting stud. If there're 3 wires then one of them is the ground and the mounting studs may not be connected to anything in the light electrically, but you can still put the ring lug from the ground wire on the stud. Just be sure that the ground lug makes good contact to bare metal on the trailer.<br /><br />If your trailer lights are mounted on the tilting portion of your trailer, then down the road if your trailer lights start to behave intermittently, you might have to put a ground strap between the tilting and non-tilting parts to maintain the ground.<br /><br />Good luck.

 

[Fishhunter38]

Re: Trailer lights

Thanks Guys the ground was the problem. Took the lights off sanded around each post and bam all lights work. Thanks again.<br />Good Luck and Tight Lines