What To Check When A Trailer Tail Light Stops Working

Updated 10/26/2021 | Published 10/25/2021

Products Featured in This Question

LED Combination Tail Light Kit for Trailers under 80" Wide - Submersible - Driver and Passenger

(3281)

$74.38

Hook Probe Circuit Tester

(61)

$13.33

ONE LED Trailer Light w/ Flange - Brake, Tail, Turn - Submersible - Round - Red

(80)

$12.44

Question:

1 of 2 left side tail/brake led light does not work. Although the LEDs work fine when brake pedal is applied. All other lights work fine as well. There is power going to light connection.

asked by: Robert P

Helpful Expert Reply:

If the brake light is working, but not the tail/running light, there will be one or two things going on.

First, the LED has gone out and the light will need to be replaced. This does happen after a while and is a pretty common occurrence. Quick and easy way to test this is to use a tester, like the # PTW2993, to make sure you are getting power to the light through the plug. You will need to determine which port is your ground, but the port for the brake should only have power when the brake is pressed, and the running/taillight should have power at all times.

If you have power, the light will need to be replaced. If there is no power, you have a break in the line somewhere and will need to find it, repair it, and retest. This should get you back up and running.

If you do need to replace the light, we should have a good replacement for you. The picture makes it look like the ONE LED Trailer Tail Light - Stop, Tail, Turn # STL003RFLB could be a good option, but if you can tell me the brand and size of your current light, I should be able to find something for you.

expert reply by: Lazer S