Both Trailer Turn Signals Blink when Running Lights Are on and Turn Signals Engaged

Updated 02/22/2012 | Published 02/19/2012

Question:

with running lights on trailer, turn on blinker and both come on. I ran a ground wire to trailer, its a tilt trailer. any ideals how to fix this problem? thanks

asked by: scott C

Expert Reply:

This does sound like a ground problem. If it only happens when the running lights are in it indicates a ground issue because ground problems normally show up when there is more of a load on the system.

First, make sure that the main ground from the trailer plug is attached to a clean and corrosion free bare metal surface. Next, go back to the lights. Most trailer lights ground through the mounting studs if there is not an obvious ground wire. In either case, the grounds have to be attached to a clean and corrosion free bare metal surface.

You mentioned it is a tilt trailer. It could be that some of the wiring has been pinched and the copper inside is exposed and touching the trailer frame. Inspect the wiring for anything like this and repair as needed. Running a jumper ground wire from the tilting portion to the non tilting portion of the trailer will most likely fix the problem. The trailer connector is grounded to the non tilting portion, but the lights are most likely attached to the tilting portion.

The two portions of the trailer probably use bolts as the pivot point. When the trailer is new, this usually works well. After a few years, this pivot point can wear and loosen up, therefore not keeping a continuous ground connection.

You can also make sure the trailer and vehicle side connectors are free of dirt and corrosion.

expert reply by: Michael H