Do I Need a Brake Light Relay When Flat Towing a 2026 Jeep Grand Cherokee?
Updated 08/27/2026 | Published 08/21/2026
Products Featured in This Question
Question:
Flat tow Vehicle: 2026 Jeep Grand Cherokee Summit When using the Blue Ox Patriot Portable Flat Tow Brake System: Do I need to disable/modify the vehicle brake light when installing the Blue Ox 4-Diode Universal Tail Light Wiring Kit for Towed Vehicles
asked by: Ernie G
Expert Reply:
Hello Ernie,
Great question. I can't give you a direct answer, but I can tell you want to do to find out. It all depends on whether the brake lights on your 2026 Jeep Grand Cherokee Summit come on when the brake pedal is pressed with the Jeep set up in flat-tow mode.
The Blue Ox Patriot Portable Flat Tow Brake System # BLU37TR physically presses the Jeep's brake pedal. If that causes the Jeep's factory brake lights to illuminate, they can override the turn signal coming from the motorhome through the Blue Ox 4-Diode Universal Tail Light Wiring Kit # BX8848. If your brake lights do come on in flat-tow mode, you will need the Roadmaster Brake-Lite Relay Kit # RM-88400. The relay prevents the Jeep's brake light signal from overriding the motorhome's turn signal while you're towing.
If the Jeep's brake lights do not illuminate when the brake pedal is pressed in the required flat-tow mode, then the relay is not needed. I would set the Jeep up exactly as the owner's manual specifies for recreational towing and test the brake pedal before adding the relay.
Where is the first big trip after you get everything set-up?
Product Page this Question was Asked From
Blue Ox 4-Diode Universal Tail Light Wiring Kit for Towed Vehicles
- Flat Tow Wiring Harness
- Splices into Vehicle Wiring
- Diode Kit
- Universal Fit
- Blue Ox
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Vehicle Tow Bar Wiring
- Video: Roadmaster Smart Diode Kit Installation Guide - 2026 Jeep Wrangler Unlimited
- Shop: Vehicle Tow Bar Brake System
- Search Results: 16 gauge wiring
- Search Results: air force one braking system
- Video: Demco Air Force One Flat Tow Brake System - 2019 and Newer Spartan K2 400 RVs Comprehensive Review
- Shop: Curt Custom Tail Light Wiring Kit for Towed Vehicles
- Search Results: high~low adapter hitch adapters
- Search Results: running boards
- Search Results: battery charger
- Search Results: brake lite relay
- Search Results: demco air force 1
- Shop: Curt Universal Tail Light Wiring Kit for Towed Vehicles - 4-Way Flat Connectors
- Video: Setting Up Your CURT RVibrake Battery Charger - 2020 Jeep Gladiator
- Shop: Demco Stay IN Play DUO Inline Air Pressure Regulator
- Shop: Demco Air Force One Flat Tow Brake System for 2019 and Newer Spartan K2 400 RVs w/ Safe Haul
- Q&A: How To Tell If My Jeep Needs A Brake Light Relay When Flat Towing
- Shop: Roadmaster Smart Diode Kit for Variable Voltage LED Tail Lights - 7-Way to 6-Way Adapter Cord
- Shop: 16 Gauge Primary Wire - Black - Per Foot
- Shop: Demco Wireless Coachlink Braking Monitor for Flat Tow Brake Systems
- Q&A: Installing Roadmaster Invisibrake/ Finding Brake Switch Wire 2024 Jeep Wrangler
- Q&A: Brake Light Relay to Prevent Motorhome Turn Signals Being Overridden By Brake Lamp on Towed Vehicle
- Video: Curt High-Low Adapter for Tow Bars Spec Review
- Video: The Low-Down on the Roadmaster Hitch Riser for Tow Bars
- Video: Setting up the Curt Custom Tail Light Wiring Kit for Towed Vehicles on a 2023 Jeep Wrangler
- Video: Complete Breakdown of the Roadmaster Universal Stop Light Switch Kit
- Q&A: Winnebago with Seperate Taillights Towing a Jeep and Troubleshooting Brake Lights not Working
- Q&A: Where to Install Diodes when Installing Roadmaster Invisibrake with Tow Bar Lighting
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Article: Trailer Wiring Diagrams
on Flat Tow Wiring Harness
Mal
8/26/2026
No, you do not have to modify the vehicle break light system. Wire as directed, and it will work fine. You will get the break or tail light when giving a turn signal as opposed to the different color and location of the vehicle turn light. The vehicle's turn signal will work as prior to install of the kit.