Trailer electrical question

[Craig D Peltier]

Hi, I have a small trailer thats only 8 feet long. The right tailight and blinker doesnt work. I checked for continuity with a tester 6 icnhes before light and its good. I also checked for any exposed wires and taped them up in case it was grounding out. The ground out of plug that I attach to a small bolt on trailer must be working incorrectly cause I cant get it tight but no doubt the ground is touching the metal of trailer.
I changed the bulbs, I know its not a fuse cause the left side works.
Any suggestions what else? I can replace the wire to that side? I do have a voltage tester but never have used it nor I have I opened it.

So ground? The wires coming in to taillight are 6 inches long, where its soddered to back of each bulb insert. I cant see them but the chance of both bulbs sodders off are slim.

Thanks

[mark page]

Some helpfull suggestions. First check the vehicles trailer harness plug/connector with your voltage tester or DVOM for voltage with the turn signal or brakes applied. If there is no voltage present during this, the problem lies with the vehicles electrical system. Check for proper connections etc with the wiring harness on the vehicle. Next, some vehicles have each side on a separate fused circuit. Lots of Mopar vehicles are like this. Double check all fuses. If your voltage signal is good on the vehicle, the problem lies with the trailer. Common problems are corrosion on the bulb socket terminal contacts, chaffed wiring, and proper grounds. Hope this helps.

[Jim O'Dell]

If the voltage tester you talk about is a volt/ohm meter, break it out and use it! I'd test continuity of the ground circuit using the ohm part of the meter by attaching one lead to a known good ground, and then the other to the ground of the bulb's socket. ( Use the ground for the light on the other side of the trailer since it is working properly) You should get a reading, if not, the ground circuit is bad. Could even be the wire inside the insulation is broken. Not a normal thing, but it does happen. If the ground is good, switch over to voltage and hook the ground wire to the ground of the socket, and use the probe to touch the positive lug of the socket. If no reading (someone stepping on brake of course. :D ) then something is off in the positive wire between where you probed earlier and the socket...again could be a broken wire.
Now you mention the bolt will not tighten up for the ground wire. Replace that. There could be just enough resistance to keep the wire from making good contact for the ground. In fact, I'd do that first.
Good luck! My guess from what you have said is that the problem is in the ground wire of the set up. Jim.

[Craig D Peltier]

Thanks I will report back with what I find.

[Mike Cutler]

Little more info needed if you still can't find the problem.

Make of Vehicle.
Amber lite in the rear or not
Wiring harness adapter, or T- connector set model and part#
Are there any plug conversion. 5-4, 7-4 etc.