Why Would a Right Trailer Taillight Stay on After Vehicle is Turned Off

Updated 08/26/2014 | Published 08/25/2014

Question:

my right trailer light stays on all the time, even when the car is off. is this a ground problem?

asked by: Bob F

Expert Reply:

Typically when a trailer function stays on after the vehicle has turned of the problem is a fried aftermarket 4-way converter box. Or, if the lights are LEDs sometimes you will see the lights dimly lit.

If you have an aftermarket 4-way converter box installed for trailer wiring on your vehicle most likely it has shorted out. Check out the video I attached that details how to test it.

These don't usually short out for no reason, before you replace the harness you will want to find the short on your trailer that caused the problem and fix it prior to installation of the harness.

expert reply by: Jameson C