lights not working on my trailer???

[stephenc8301]

the lights on my trailer do not come on when my driving lights are on at nights. but when i push on the brake the brake lights work? i dont know what to replace or how to check each connection.

 

[External Combustion]

Re: lights not working on my trailer???

You are going to have to get a continuity light or a volt, Ohm meter to check out your system. First see that the vehicle plug gives the proper voltage to the running lights on yhour trailer. Standard code lists the brown wire as the running lights. No voltage or too low equals no lights. Correct it.

If you have the proper voltage atr the vehicle plug, trace the wires out to the lights on the rear of the trailer. Improper voltage there is a no go also. Correct the wires up to the lights if needed.

The last aspect would be corrosion on the light bulbs or light fixtures. Polish, check, replace if needed. Normally if you have stop lights on each side the fixtures are OK, but not always.

 

[txmntman]

Re: lights not working on my trailer???

trailer lights, especially boat trailers, are notorious for not working, getting fixed, and then not working again.

One time, I got my trailer lights to work once in a row!!

 

[Silvertip]

Re: lights not working on my trailer???

Trailer light connectors are "cheaply made" and often covered in corrosion. Clean the terminals or at least connect, disconnect, and reconnect them several times. This action can clean the terminals for a little while.

 

[mrmushroomman]

Re: lights not working on my trailer???

I agree with cleaning and checking voltage. I would also make sure your grounds are good. I had the same problem this year and it turned out to be a fuse on my truck that was blown. My license plate lights quit working and my trailer running lights were not working. Found blown fuse and cleaned all grounds on trailer and they now work perfect. Good luck.

 

[CAVU V]

Re: lights not working on my trailer???

Same thing happened to me a couple of weeks ago. Some of the splices in the pig tail from the trailer to the connector you plug into your tow vehicle were broken.

 

[tashasdaddy]

Re: lights not working on my trailer???

http://www.accessconnect.com/trailer_wiring_diagram.htm

running an dedicated ground wire to all lights also eliminates problems
http://forums.iboats.com/showthread.php?t=240285

 

[njlarry]

Re: lights not working on my trailer???

Ditto all above. Also if you have a disconnecting trailer tongue the ground conector can be rusted. I now have two ground points on my trailer frame, one on the removeable tongue and one one the main frame.

 

[BamaAlum97]

Re: lights not working on my trailer???

When I had problems with my trailer lights, I got myself a cheap voltmeter from Radio Shack...First step was to check the voltage coming out of my tow vehicle...then check it again at each light...find the low voltage...re-terminate...and done...

Trailer lights are always a PITA!!!

 

[tashasdaddy]

Re: lights not working on my trailer???

this should be in every tool box. http://www.iboats.com/Marine_Store/...73031--submit.Search--submit.x.34--submit.y.7

 

[rndn]

Re: lights not working on my trailer???

Follow TD's advice and run a dedicated ground wire to each light. It just about eliminates current and future problems.

 

[bruceb58]

Re: lights not working on my trailer???

Follow TD's advice and run a dedicated ground wire to each light. It just about eliminates current and future problems.

Very unecessary and can cause its own problems. If every light has a clean attatchment to the frame of the trailer and the ground on the plug from the vehicle also has a good clean attatch point, you will never have a problem. By adding a seperate ground to the light(I assume you are using the mounting stud) that attach point has to be just as good as a connection to the frame. If you are going to go through all the trouble of making that point a good connection, why not just make its attach point to the frame just as good of a connection?

I have had boats for over 30 years. I never have a ground problem.

When your seperate ground fails, you are going to have to track down which point on your ground wire has either broken or a joint has failed. I subscribe to the "KISS" principal. Seperate ground wire to lights violates that principal.

 

[samo_ott]

Re: lights not working on my trailer???

Pretty much as many trailers as there are out there the owners have had wiring problems at one time or another. Especially on boat trailers. (except for bruceb58!)

 

[Bt Doctur]

Re: lights not working on my trailer???

remember that some vehicles use a separate fuse panel for just trailer applications.you lose the trailer but keep the tow vehicle lighting.
Ford for example.Test the trailer lighting with another battery .ground to trailer frame and test each trailer plug pin.test the vehicle connector next.
double check the ground wire connection. next read your owner manual to see if trailer circuits are fused.

 

[tashasdaddy]

Re: lights not working on my trailer???

bruceb58, and i have gone head to head on the grounding issue of the trailer, he has his opinion and i have mine, been doing it for over 20 years, and will keep doing it. he won't change my mind.

 

[burp]

Re: lights not working on my trailer???

If the tow vehicle is a Ford F150 or Explorer, check the fuse panel in the engine compartment. There is a 20 amp fuse that powers only the trailer marker lights. If the fuse is blown, all the tow vehicles lights will still work fine as well as the trailer brake and turn signals.

 

[Captain Caveman]

Re: lights not working on my trailer???

Ford Rangers (just for extra info) have a trailering fuse in the passenger-side fuse panel as well. My snowmobile trailer always shorts out that 10amp mini-fuse.

 

[bruceb58]

Re: lights not working on my trailer???

Pretty much as many trailers as there are out there the owners have had wiring problems at one time or another. Especially on boat trailers. (except for bruceb58!)

By using the ground of the trailer, you actually prevent wiring problems.

It all a matter of preventative maintenance and setting up your lights properly the first time. Adding a separate ground is a band-aid for a poor setup. Once the band-aid breaks, you will be back to your original problem.

I am not trying to change your mind, TD. This is a second opinion to yours.

 

[burp]

Re: lights not working on my trailer???

Stephen,
Check the under hood fuse block for a fuse marked "TRL PARK". It powers the trailer marker lights.

Another option, isolate the problem to either the tow vehicle of trailer....... If you have a 4 pin flat electrical connector, turn on the tow vehicle lights and measure for 12 volts between the white (the odd pin in the connector) and brown (the pin next to the odd pin in the connector) wires. If you have 12 volts with the trailer disconnected, then most likely the problem is in the trailer. If you don't measure 12 volts, then most likely the problem is in your Sierra.

 

[johnnyd]

Re: lights not working on my trailer???

I have light problems every year. It is always at the start of the season. Mice chew through or expose the wire inside the frame. I change my wire harness every year. I's easy cut your old wires from the front of the trailer tie the new wires to the old wires and fish them through the frame. It takes about an hour. and the cost is cheap. All season no problems.