Can Brake Light Relay RM-88400 Be Installed on a 2018 Jeep JL Wrangler Unlimited
Updated 08/23/2025 | Published 07/03/2018
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Question:
I have a 2018 Jeep Wrangler JL and this kit doesnt seem to work for my application even though I was told that it would. Call your tech support and was told to call Jeep. Have you actually installed this brake light system in a 2018 Jeep wrangler? Need help figuring out how to install or I will have to tear it out and go with a different system.
asked by: Frederic T
Expert Reply:
The problem with the 2018 Jeep JL Wranglers is that the circuit you need to install the brake light relay # RM-88400 is inaccessible but it isn't required on this vehicle. When your JL Wrangler is set up in flat tow mode (see owner's manual) the brake light circuit is not active. That is why we do not list it for that particular vehicle. When in flat tow mode it will work fine.
Or you can avoid all together by going with magnetic light kit # RM-2120.
If your braking system has a monitor that indicates that the brake pedal in the Jeep is moving then you will need stop light switch kit # RM-751490 for that monitoring system to work (since the brake light circuit is not active in tow mode).
Product Page this Question was Asked From
Roadmaster Brake-Lite Relay Kit for Towed Vehicles
- Flat Tow Brake System
- Brake Light Relay
- Roadmaster
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Gene
8/23/2025
I have a 2022 JL so I think I have the same issue. The brake lights are controlled by the BCM (body control module) and there is no fuse accessible. Because my brake lights come on with the ignition off a Roadmaster 88400 was recommended. If I am understanding your explanation to Frederic correctly when I put the JL in Neutral for towing my turn signals will function correctly? A forward thinking function built in by Jeep?