How to Wire a Third Brake Light on Trailer
Updated 09/20/2024 | Published 04/03/2015
Question:
I want to install a 3rd brake light LED to my trailer - I have already changed out the other lights to LED = but which product do you recommend and how do you tell it to only come on with the brake? Do I need some sort of converter?
asked by: Larry D
Expert Reply:
Since your trailer uses a combined wiring system where the stop and turn signals run on the same circuit, in order to add a third brake light to your trailer you would need to use a 2-Wire to 3-Wire Converter, like part # 118158. This will convert the wiring to a separate system which would allow the third brake light to only come on when braking.
To wire the converter you can start with the input side, white wire needs to be grounded to a clean bare metal surface, green taps into the right turn circuit on the trailer and yellow taps into the left turn circuit. Next is the output side, yellow and green wires are not needed in this case so you can just cap them off and the red wire will connect to the colored wire, in this case red, on the third brake light. Keep in mind that the white wire on the third brake light will need to be grounded as well. I have attached a wiring diagram for you.
Product Page this Question was Asked From
2-to-3 Tail Light Converter for Towed Vehicles w/ Incandescent Tail Lights
- Flat Tow Wiring Harness
- Splices into Vehicle Wiring
- Tail Light Converter
- Universal Fit
- Tow Ready
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on Flat Tow Wiring Harness
John
9/20/2024
Hello. My enclosed trailer currently has 2x Optronics 3 wire LED Stop/Turn/Tail Lights and an Optronics center light that is mounted up high in the center of the trailer but only functions as a running lamp. Can you tell me which tail lamp wires I need to tap into to get brake lamp power out of the module? My trailers tail lamp wiring is black=tail, red=stop/turn, white=ground. Thanks, -John