Troubleshooting Trailer Lights that Don't Work When Headlights are On

Published 10/14/2015

Question:

Brake lights, turn signals and emergency flashers work on trailer but lights will not go on when tow vehicle headlights are turned on. The brake, turn signals still work but tail lights wont go on nor will lights at trailer corners nor highlights on back and front of trailer.

asked by: Tim Q

Expert Reply:

It sounds like there is too much amperage being drawn on your trailer when the headlights are on and it is too much for the trailer so everything shuts off. This could be because of a bad ground somewhere.

First thing I would do is check the grounds on the trailer for any loose wiring and corrosion and fix as necessary. If the grounds are good you might need to convert your trailer lights to LED lights so as to minimize the draw on the trailer light circuits.

LED lights draw a fraction of what a incandescent bulbs draw and should work well on your trailer. I attached a link to a page that has our LED light kits for trailers for you to check out.

expert reply by: Jameson C