# Trailer lights problem



## albright1695 (Dec 27, 2011)

When I plug up my trailer lights to my tow vehicle the trailer lights dont come on and my taillights on tow vehicle get dim. Anyone know whats causing this? And how to fix?


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## sixgun86 (Dec 28, 2011)

I'd check your grounds first at the tongue and back at each light. They sell a trailer light tester at walmart for around $10 that might help you diagnose your issue if vehicle related. Probably pay the same to have a trailer joint do it for you.


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## nomowork (Dec 28, 2011)

Grounded wiring?

Pull out trailer light bulbs to see if trouble persists then check for a ground on each wire on the trailer.


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## See Chris Fish (Dec 29, 2011)

Sounds exactly like the issues I was tracing down on my trailer. It's definately a grounding issue. I finally got sick of trying to track down problems and just re-wired the trailer lights myself. Walmart has submersible LED lights for around $50, get some submersible side markers, and a roll of 16 gauge white wire. I found that running a dedicated ground wire, straight from the lights to the tow vehicle's harness works best.
Save yourself the headaches and just re-wire.


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## Stefan (Dec 30, 2011)

as previous posters said, check the grounding. Check all grounding points, make sure that they arent inhibted by corossion, rust or paint. IF so grind away to the metal and re-ground. Bet you that'll fix it


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## Bob Landry (Jan 21, 2012)

If anyond has done any recent wiring on your trailer, my first choice is someone connected a hot wire to ground.
If your TV lights dim, you don't have a bad ground. That's too much current being drawn and a bad ground doesn't allow current to flow. You have something shorted to ground putting large load on the 12V coming from the truck. You have a hot wire that has had the insulation worn through and is shorting against the trailer frame. You could probably figure out where it is, but un that time, you could pull a whole new wiring harness. Beside, if there's enough wear on one wire to cause a problem the others probably aren't far behind. I just rewired my trailer because it was a salt water rig with all of the problems associated with that. The wiring harness cost me $10 along with another $10 for white wire to do the grounds. I ran a hard wire grounds to all of the lights because I just don't trust screwing the wire to the chassis to complete a ground. I also don't care for suitcase connectors, but that's just from seeing years of problems in marine wiring. Its not any more work to pull a ground wire, you just tape the whole bundle up to the fish tape and pull it all through at once. I also soldered all of my connections and then used the heat shrink that has the glue that melts when it gets hot. It makes the installation bullet proof. The last thing I want is to get pulled over by some over-zealous cop because a side light isn't working. I still need to replace all of my side lights because they were corroded beyond usability, but I left enough slack so that I can rech in and get the bundle to splice into.


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## rickybobbybend (Jan 21, 2012)

Bob Landry is right on the money. The key is the dimming of the tow vehicle's lights. Save a lot of frustration and replace the system.


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