Troubleshooting Trailer Tail Lights That Stay Lit When Running Lights are On

Updated 10/30/2018 | Published 10/29/2018

Question:

I have a 1987 Coleman Pop up camper. I am replacing the back end with aluminum diamond plate. I am installing new tail lights. The new tail lights have 2 white wires, green, yellow, and black. Everything is wired up and will work with the vehicle lights off blinkers and brake. When the vehicle lights are on the tail lights stay lit. The new tail lights have 2 white wires, when connected together to the white trailer light same problem white trailer wire is ground to the frame and I have cleaned and reconnected this ground. I have just one white wire connected currently, same problem with the 2nd white wire not connected to anything. Should I ground the 2nd white wire to the screw for the light mount? Do both 2nd white wires have to be ground independently to the individual light screws to complete the circuit? Or do I have a larger problem? Thanks for the help

asked by: Sarah D

Expert Reply:

You are on the right track by checking your connection points and grounds. Even though a white wire is typically associated with the ground that is not always the case. The headlights of your tow vehicle will cause the running light circuit of your trailer to leave the clearance lights on but if your brake lights are on then that is a problem.

I would start off by making sure that you have all of the wires installed to the correct function. Since wiring is not required by law to be certain colors you could have simply connected some functions together that were not supposed to be connected together.

If this doesn't fix your problem let me know what light you have and I can help you troubleshoot further.

expert reply by: Jon G