Troubleshooting Right Tail Light Does Not Turn On but the Right Stop, Brake and Turn Signals Work

Question:

All the lights work fine but the right rear does not work as a running light but stop,brake and turn works?

asked by: Billy

Expert Reply:

It sounds like you have a weak ground on your right light. Start by making sure that your right light is securely grounded to a clean part of the trailer frame where there is no rust, corrosion and paint. Also check the main vehicle wiring grounds to make sure they are attached to a clean surface. Then check the brown wire with a circuit tester # PTW2993 to make sure power is running through it. The brown wire runs power to the taillights, so if no power is going through this wire when the taillights should be on, there is a problem with the wiring harness.

If this is the case, you will want to check the wiring to see if there are any broken, frayed or pinched sections that could prevent power from reaching the taillight. If all of the other running lights are working on the trailer, then the problem is most likely not on the vehicle.

If you check these places and the problem is still occurring, let me know and we can troubleshoot further.

I attached a wiring diagram and wiring help article you may find useful. I also attached a 4-pole troubleshooting help article you may find helpful as well.

expert reply by: Sarah H