Weird trailer light issue

[Jeff Hahn]

I'm heading to our cabin on Georgian Bay in the morning and have an issue with my trailer lights that I can't figure out.

I have LED trailer lights on my Lund Trailer, hooked to my 1993 Suburban. Running lights, turn signals and brake lights work on the truck. On the trailer, I have brake lights, turn signals on both sides, but a strange deal with the running lights. On the starboard side of the trailer I have no running lights. On the port side of the trailer, 2 of the 12 little LED lights in the trailer light are working, but not the other 10.

I know that 90% of trailer light problems are due to a bad ground. But, if the ground was bad, none of the other lights would work...but I checked it anyway. I checked the fuses under the dash. I wire brushed contacts on the pigtails on both the trailer and truck to remove any corrosion. I figure it has to be the brown wire and I traced it but don't see any breaks or places where the insulation is rubbed off.

Any ideas or suggestions?

[Amistad Tackle]

Hmm. First check voltage at the pigtail with the lights on. Then I would check the voltage at the trailer lights. Use a pin to probe the wire and a digital volt meter. If the voltage is low st the lights you likely have a partially broken wire or corrosion inside the insulation. You will have to isolate where that is. Since it is both lights it is likely before it splits from the trailer harness. I have seen wire inside the insulation break or corrode and either cause intermittent or low voltage issues.

[Altro Cat]

Could be the light itself. A lot of times when LED lights fail they do exactly as your describing, I see it everyday with big trucks at work.

I also have the exact same issue happening right now on my boat, passenger side tail has several LEDs out but they all burn when I hit the brakes.

[Jeff Hahn]

Thanks for the suggestions. I also posted in the Lounge, since the traffic on this board is not too high on the weekends.

http://www.bbcboards.net/showthread.php?t=827054

I connected the trailer to my Blazer and the exact same problems are still there. So, at least that rules out the Suburban...it's in the trailer somewhere. And, when I hooked up the Blazer, I connected the pigtails without the coupler on the ball, so I know the ground wire from the truck to the trailer is good.

The good news in all of this is that I will be traveling during the day, so I shouldn't need the running lights...except for the first 30 minutes or so until the sun gets up. But, those are all back country roads, so I should be good...I hope.

When I get home I will have to spend some time under the trailer trying to find the bad spot in the brown wire.