Will Third Brake Light Work when Flat Towing 2017 Jeep Wrangler Unlimited Behind an RV

Question:

hello. i just installed the brake relay kit part #88400 on a 2017 jeep unlimited jk. This was done to make my jeep towable using the Blue Ox Patriot Radio Frequency, Portable Braking System - Proportional Item # BRK2012 and the Hopkins Custom Tail Light Wiring Kit for Towed Vehicles Item # HM56200. After the install my third brake light does not work with either key on or off. What can i do to fix this issue?

asked by: Kury G

Helpful Expert Reply:

I spoke with our installation manager and found out that the third brake light on newer Jeeps like your 2017 never light up in these situations. The issue is that it is on its own circuit and the brake light relay, which allows the turn signal lights to function properly when braking, doesn't allow the third brake light to illuminate.

It is possible to get it to light up but you would have to have another converter, # 118158, which would tap into the combined right turn/brake and left/turn brake wires on the Hopkins wiring harness and then on the output side you would cap off the yellow and green wires and run the red wire to a diode, # RM-790. The other input on the diode would be for the factory power wire to the third brake light. Then on the output side you would run a wire from it to the power wire on the third brake light.

Considering all the extra parts and labor, and the fact that the third brake light is not required while flat towing the Jeep, it may not be worth the trouble but that is up to you. It can be done but it isn't easy.

expert reply by: Michael H