Trailer lights not working

[dperkinstx]

I just ran new wires through my galvanized trailer. The ground wire is attached to one of the large bolts that holds the hitch to the trailer.

I have a circuit tester that has a needle point on it and an alligator clip on the other. If I clip the alligator clip to my truck and poke a wire, my tester lights up. However, if I clip it to anywhere on the trailer I get nothing.

I'm pretty sure I have a ground problem. I'm looking for suggestions on how to get the trailer grounded.

 

[smc0922]

Check ground at the truck trailer plug. Probably not connected. Use a paper clip and probe the ground terminal to your clip, then probe the light wire.

 

[dperkinstx]

My tester looks like an ice pick with a light bulb in the handle. A wire comes out of the end of the handle. That wire has an alligator clip.

If I clip the alligator clip to something steel on my truck I get the tester to light up when I touch the running light part of the plug. If I clip the alligator clip to the ground prong on the plug, then touch the running light prong, I get nothing. Should I get a light when I do that?

 

[Coastiejoe]

Many systems use the trailer as the ground through the ball itself. With age, grease and rust make this a poor connection.

Run a separate wire from your vehicle to the trailer to give a quality secondary ground.

 

[RFoster130]

Many systems use the trailer as the ground through the ball itself. With age, grease and rust make this a poor connection.

Run a separate wire from your vehicle to the trailer to give a quality secondary ground.

I totally agree. sounds like you have a ground issue. Most trailer light problems are attributed to a bd ground. Instead of grounding with that bolt i would use the ground coming from the vehicle plug.