Activating 3rd Brake Light on 2020 Jeep Wrangler While Flat Towing

Question:

I purchased the wiring harness RM-154 and installed it on my jeep. it works perfectly with my 2017 Winnebago Sprinter MH. Thanks for the video installs. I would like it if the 3rd brake light over the spare tire would come on too. Im sure there is a way to add it to the system, but do I need a separate diode? Thanks,

asked by: Tim S

Helpful Expert Reply:

The 3rd brake light on the 2020 Jeep Wrangler runs on a separate circuit from the other lights, and the Roadmaster Universal Hy-Power Diode Wiring Kit # RM-154 and any other tow bar wiring kit, do not provide for a way to connect to those circuits.

With that said, it's not going to be as simple as just adding a diode to the setup and it might not be worth the added trouble. But, if you wanted the 3rd brake light to operate 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.

expert reply by: Erik B