Troubleshooting Weak Trailer Taillights

Question:

I have an issue. I currently installed a new wire harness for my trailer hook up on my van. I hooked it up accordingly with the color and left,right turn signal and backlights. I have very little voltage going to the break and signal lights. I just purchased his trailer when I push the breaks the lights completely turn off. If I hook up a white excess wire to the harness it illuminates well bohe breaks and turn signals but that causes my trailer running lights to burn out. I cant seem to find the problem other than maybe I may need new bulbs or not enough ground. but where would I check to begin with, a bit frustrating. any feedback would help a ton. Thanks

asked by: Irving

Expert Reply:

At least one of the problems you have is insufficient grounds. First you will want to make sure that all of your taillights are grounded to a clean metal surface. You also want to make sure the main ground for the trailer is connected to a clean metal surface.

If the bulbs of your running lights burn out when you run a jumper wire on the ground circuit that would most likely indicate that you are overdrawing the circuit or you are jumping the wrong circuits which is causing a short.

I would try improving the grounds like I stated in my first paragraph and that should make the problem go away.

I attached a couple FAQ articles that you should find helpful as well.

expert reply by: Jameson C