What Do the Black and Red Wires on Trailer Tail Lights Connect to?
Updated 08/15/2025 | Published 07/21/2025
Question:
Question with wiring. Im e-wiring my trailer with LED lights with the gromet. What color wire goes to what ? does the yellow/green wire go red or black?
asked by: Tim D
Expert Reply:
Hey Tim, thanks for reaching out!
You'll need to match the wires per function, which it seems you've found out. I'm not sure what function your yellow/green wire carries, but typically the black wire is for the tail/running lights and the red is for the stop/turn signal. We see this with the Optronics Light Kit # # TLL12RK.
The nice thing about trailer lights is that if you end up being wrong, you can simply swap the wires around and be good to go. I recommend testing the functions while the wiring connections are easy to still access.
Product Page this Question was Asked From
Optronics Fleet LED Trailer Tail Lights w/ Grommets - Stop,Turn,Tail - Submersible - Oval - Qty 2
- Trailer Lights
- Tail Lights
- Brake/Tail/Turn
- Oval
- Recessed Mount
- Submersible Lights
- LED Light
- 6-1/2L x 2W Inch
- Red
- Optronics
more information >
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Jon G.
8/15/2025
Hey Tim, how did the wiring go with your trailer lights? Did swapping the wires help you get everything working correctly? I'm curious because it might help others who are rewiring their trailers too!