trailer lights

[jccams]

Last week I pulled the trailer North. All lights running, and stop/turn were working. Left trailer parked at friends house the whole trip never unhooked. Drove it around the pole barn once to move for plowing, lights worked then. Loaded up to leave, no running lights, brake/turn were fine.

Got home and started checking found the 15a fuse in truck for trailer running lights blown. Checked trailer with ohm meter from running lights to ground expecting a dead short and it is fine. Checks same as brake/turn lights.

Replaced fuse in truck but haven't plugged back in yet. Anyone had this happen and not found anything. Harness on trailer does not look damaged. Going to plug in this week-end and check. Anyone have suggestions about what to look for? Don't want to get 10 miles into a trip in the dark and blow a fuse again.

Thanks
Jeff

 

[the_weasel]

Yes. I have had it happen twice on two different tow vehicles and trailers. Never figured out the cause but once the fuse was replaced everything has woked properly. I carry a spare fuse now just in case.

 

[snowfish]

Fuses generally blow due to an intermittent short. And strangely enough, sometimes by pure magic! Like stated before.

I'd go directly to the license plate light. On open trailers they take the brunt of the attack of road debris & snowbanks. On enclosed trailers the wire is routed through the ramp door (for the most part) and bends everything it's opened and closed. It could be getting pinched too.

Put in a new fuse and see what happens. Make sure all of the running lights are working. If not, one may have come unplugged and occasionally grounding itself to the frame.

Cheers.

 

[yamadooed]

You have a short or a ground.

 

[vw56german]

I am wondering if the simplest solution is being overlooked. The vehicle has a 15 amp running light circuit. That is not a huge power circuit and I wonder how many more bulbs it would take to put the actual current draw up to the 15 amps. Could it be that this trailer just has enough extra lights to max out the trucks running light capacity? If a fuse has near its maximum current pulled on it long enough heat will take its toll and that fuse can fail. I would carry 2 spares. <grin>

 

[jccams]

I bought the trailer new in 99 and have always towed with the same vehicle. This is the first fuse I have blown. It does not have any of the high lights on the shell only those that would be on an open place so I doubt it is maxed out, but fatigue could certainly be a factor. I am leaning towards an intermittent short. Who knows maybe it will not happen again.

Forgot to add the 15amp fuse is only for the trailer running lights, truck running lights are on a different circuit.

 

[dafalls]

Got pulled over last weekend south of Rogers City for no trailer lights. Put in a new fuse and no luck. Put in another fuse when leaving the cabin on Sunday and the lights worked all the way back. Go figure.

 

[onesnowman]

Trailer lighting

You didn't say if it was a tilt or drive off, if it's a tilt and you had lights going up check were your tilt pin (bolt) connects to the platfrom. You'll have to tilt the platform as the wiring is pulled more in the tilt position and you may is the area that caused your problem, also look under the rear of the platfrom as some manufactors don't enclose the back of their lights and after a few drive on/offs the wiring gets pinched in this area. A cheap test light is a great investment. Good Luck

 

[heckler56]

I had a similar thing happen. All of my wiring was routed in the frame. After time the wire got brittle and chaffed on a inside corner. Taped it up and was good for another year, then it happened again. Finally rewired the whole trailer to resolve it.

Check what wire you can see exposed and see if the casing has become brittle.

 

[bigfoot]

Same thing happened here. It was so much quicker to re-wire the trailer If you have an old extension cord laying around, it should be cheap too. Good luck!

 

[jccams]

Just got done hooking up the trailer. All running lights are working fine, including license plate illumination. I pulled and wiggled the harness on the trailer and still fine. Looked at all the exposed wires and see nothing wrong. Can't fix it if it isn't broke. Have spare fuses in the truck just in case. Guess I'll see next trip.

BTW...it is a drive on/off enclosed R & R.

Thanks for all the input.

Jeff