Trailer Light question
 

when I turn on my right signal light my boat trailer back lights both flash. When I turn on my left signal neither of my rear trailer lights do anything. Both come on when I press my brakes. Where do you think the problem is? The little display lights on my adapter that plugs into my truck individually flash when either signal is turned on. Seems like it would be anywhere from my flat connector on my trailer all the way to my butt connectors going to my rear lights on my trailer. Any suggestions?

almost easier to run a new set of wires than try to find a small spot where it may be nicked and corosion has set in. Check your ground and your connections at the back first though, may just need to cut em back a little and get to some clean wire.

I fought with mine for a long time before I gave up and just re-ran everything. Should've just done that in the first place.

I would check all connections first. Had a truck that when I turned the blinker on, it would blink super fast. Come to find out, a connection underneath the bumper had started to come apart.

Here is your answer. I had the same problem and the lights, not the ground wire had a bad ground. Made a grounding strip instead of counting on the bolts to ground the lights.

When you say...
 

"clean" wire, does it have to be shiny when you strip the insulation? Also, if it were simply a bad ground, wouldn't that keep the light from functioning at all?

Nope........also when redoing a ground put a little never seize on it;)

Just had the same problem with my trailer. My left signal was doing the same thing, so I re-mounted the ground for that light and it fixed the problem.

make sure it make a good cnnnection...try scraping a lil bit of the trailer to make sure it connects securely

I replaced my lights the other today with some new LED lights. Well the kit came with new wiring. Once I started taking off the old lights I realized how old and cracked the old wires were so I went ahead and changed out everything, since it was there. I got the LED kit from Harbor Freight for around $40. 2 lights, 2 yellow side lights, and a wiring harness with plug.

put a grinder to the metal first though to get a good clean surface, grounding is very important when working with trailer lights, I just fixed a guys lights where his trailer rusted around the middle where it bolted together, hit it good with a grinder and welded the joints to have a good ground "path" and it did the trick. To find this I got a 20' piece of wire and tied it to the ground screw on the tongue and went down the trailer while the lights on touching the wire to various places on the trailer until the lights started working. That showed me what area I was losing my ground. I second the new wires though, cheap and easy for the most part. I also have the harbor freight water proof leds and love them, no problems so far and I've had them for 2 yrs.

I had the same problem.... DO as shawn stated, use grinder/dremel and make a "bare spot" and then ground it with a delf tapping screw and paint over it with a rustoleum type paint to match trailer.