Troubleshooting LED Third Brake Light Installation on Enclosed Trailer

Updated 04/04/2019 | Published 04/03/2019

Products Featured in This Question

GloLight Thinline LED Trailer Light - Brake, Tail, Turn - Submersible - Red - 17" Long

(45)

$45.18

3rd Brake Light Logic Module

(194)

$19.71

Question:

Im currently in the process of installing this light as running light/ third brake light on my enclosed trailer that has LED break lights Ive used the pacer performance 3rd brake light logic module PP20-702 as well as wired in a couple load resistors so the module will recognize the stock LED trailer lights. With running lights off, all turn/ break functions as normal. The third brake light is isolated from the turn signals. The problem is when the running lights are turned on, the 3rd brake light begins to blink with the turn signals as if the 3rd brake light module isnt present anymore. I have the black wire hooked up to running lights and red hooked up to the green wire of the pacer performance module. Is there back feeding happening with the STL179RB when the running lights are turned on and turn signals are used? Any input would be greatly appreciated as my mind is beginning to go numb from thinking about this one. Thank You.

asked by: Tom B

Expert Reply:

The GloLight Thinline LED Trailer Tail Light # STL179RB and the Pacer Performance 3rd Brake Light Logic Module # PP20-702 is all that is needed because you have LED brake lights. The load resistors are not needed for your application. They are only necessary when going from incandescent lights to LED because LED lights require so much less power that there still needs to be that power draw for the system.

You may simply need to remove the resistors to have the third brake light function properly. You have the Pacer connected correctly and there shouldn't be any issue backfeeding but you may have a bad ground connection. Make sure you have your ground wire connected bare metal to metal and clean of any corrosion. You can run a jump wire to test that ground from the tail light ground on either side. Let me know if that doesn't solve the issue and we can continue to troubleshoot.

expert reply by: Jason S