Can the Trailer Lighting Ground Through the Hitch Connection

Question:

My 2003 Exiss 3 horse gooseneck trailer has some issues with the lights. It seems to me that the ground for the trailer is made through the trailer being hooked onto the ball on my truck bed. My trailer lights wont work unless it the trailers is attached to the ball. Last night I was driving home from roping and as my trailer would bounce around on the ball going down the road, the trailer lights would flicker. Trying to see how to best fix this problem. Also, auxiliary lights wont work on the trailer. Is that a hot wire issue with the truck connection? help would be appreciated. Thanks!

asked by: Denton H

Helpful Expert Reply:

In some instances the trailer will try to ground itself between the hitch ball and coupler if the trailer's own ground connection is weak or poor. The best solution is to re-establish the trailer's own ground connection.

Find the trailer's main ground wire at the trailers electrical connection. The ground should be attached to a bare section of metal that is free of corrosion and rust.

As for your auxiliary 12-volt power to run the lights in your trailer, checking to see if you are having the proper electrical signal at your trailer connection would be the best place to start. Using a circuit tester like # PTW2993, probe the 1 o'clock blade of your trucks 7-way trailer connection. This blade is the 12-volt auxiliary power circuit. If you have power, then the issue might be a dirty or corroded plug or a wiring issue on the trailer. If you have no power on this pin, then check to see if you have blown the fuse for this circuit. I have attached a photo that shows the location of the 12-volt auxiliary blade on the 7-way connector.

expert reply by: Jared P