Can 3rd Brake Light on 2018 Jeep Wrangler be Used When Flat Towing

Question:

Is there a way to include the 3rd brake light on a 2018 Jeep Wrangler JLU Sahara?

asked by: Jeff

Expert Reply:

The 3rd brake light on your 2018 Jeep JL Wrangler runs on a separate circuit so while it's possible to have it activated while flat towing the vehicle it's not something that any of the harnesses we have available are designed to work with, including the Roadmaster Diode Kit # RM-15267 that you referenced.

If you really want to activate the 3rd brake light you will need to add a converter like # 118158 that will tap into the combined turn/brake circuits on the Roadmaster harness. On the output side of the converter you will run the red wire to a diode # RM-790. The yellow and green wires will just be tied off. The other input on the diode would then be for the factory power wire to the 3rd brake light on the Jeep.

On the output side you will run a wire from it to the power wire on the 3rd brake light.

Keep in mind that activating the 3rd brake light for flat towing is not a requirement so unless you are really wanting to do this it might not be worth all the extra wiring and work that's needed.

expert reply by: Chris R