Troubleshooting Running Light Circuit of Optronics LED Trailer Lights STL59RB Not Functioning

Updated 04/10/2019 | Published 04/09/2019

Question:

I installed lights and wiring harness as per instructions, however I cannot get tail light to work. The pigtail that came with this harness has 3 poles and a ground however it has 4 wires going into the pigtail, Green, Yellow, 2 browns and a white. The yellow and 1 brown are connected to right tail light. The green and 1brown are connected to left tail light. Each tail light has a white ground which I have grounded to trailer. The White wire at the pigtail is also grounded to the trailer. Both blinkers and both brake lights work, however the tail lights will not come on.

asked by: Gary B

Expert Reply:

The black wire of the Thinline LED Trailer Tail Light # STL59RB that you referenced needs to have the running light circuit ran to it. This will operate the lower illumination of the light. I'd make sure that the brown wire on each side of your trailer is connected to the black wire of the lights and the stop/turn signal is attached to the red wire as I believe that's your issue.

expert reply by: Jameson C