trailer lights blowing fuse on tow vehicle

I am having trouble with my trailer lights blowing a fuse on the tow vehicle. Will just be driving down the road with all working well and then all of a sudden the fuse is blown. Where should I start looking?

First thing I would check is your ground wire - the white one near the trailer tongue. Usually, if your ground is not attached, the running lights circuit will short when you turn on your headlights. Make sure the ground wire is securely screwed to the trailer and makes good contact with your car's receiver plug.

Otherwise, the other possibility is that you have a worn wire somewhere in your trailer. The insulation of the wire sometimes wears off from vibration and you get an exposed section. If the wire wiggles just right while driving down the road, it can make contact with the trailer and short out. This is common, and can be a pain to fix.

Most late-model cars have individual fuses for trailer wiring: running, left/right turn etc. The fuse that is blowing is a good indication of where to start looking for the trouble spot. Make sure your lightbulbs are all 100% also, as I once has a burnt out bulb that was shorting the wiring.

Sometimes it is easiest to just pull the harness and throw a new one it. That way, you can beef up the connections in places prone to failer, like around corners and such. You can buy trailer wiring kits for less than $20. I just rewired yet another trailer, and it took about 2 hours. Your first rewire job might take half a day after chasing down all the right parts.

Yellow - left blinker
Green - right blinker
Brown - running lights
White - ground

Good luck!

Look in the spots where the wire passes through or over or under the trailer frame. As mentioned, it's often easier just to rewire.

If you have a swing away tongue, I would check around the hinge to see if some of the wires have lost some of the insulation at that spot. That is where I found mine.

i found a place where the wire is going thru the frame that the wire was real tight and there was not a grommet there. Could not see a bare wire but loosened the wire up some and taped to the wire. Will see if this helps....so far so good.