How To Activate The Third Brake Light While Flat Towing A 2018 Jeep Wrangler JL Rubicon

Updated 05/03/2023 | Published 05/01/2023

Products Featured in This Question

Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Way to 6-Way Straight Adapter Cord

(3187)

$205.66

2-to-3 Tail Light Converter for Towed Vehicles w/ Incandescent Tail Lights

(172)

$38.14

Roadmaster Hy-Power Diode - (Qty 1)

(336)

$18.91

Question:

2018 Jeep Wrangler JL Rubicon Installed Roadmaster 4-diode Universal Wiring Kit #RM-152-98146-7. All tailights, brake lights and turn signals operate correctly, even turn signals operate when towing vehicles brakes are applied. Towed by 2020 Ford F-150. Problem is the high brake light doesnt come on when all other brake lights operate. High brake light functions properly when Jeep is not connected to towing vehicle.

asked by: Eric S

Expert Reply:

Since the 3rd brake light on your 2018 Jeep Wrangler isn't tied into the same wiring you would need to use a converter like # 118158 and tap into the combined turn/brake circuits for the # RM-152-98146-7. The red output wire will need to be ran to a diode # RM-790 and the Yellow and Green wires can be capped off with some electrical tape. The other input terminal for the diode will need to be spliced into the factory power for the 3rd brake light. The output terminal of the diode will then connect to the other end of the power wire running to the 3rd brake light to complete the connection.

It is going to be a bit of work running the wire so most people just leave the third brake light off to avoid the hassle.

expert reply by: Kevin C