What Wire Does Red Wire of Roadmaster Brake Lite Relay Connect To
Updated 02/24/2026 | Published 02/21/2026
Question:
Im installing a Roadmaster brake light relay RM 88400 on a 2019 f 150. Does the red wire connect to the brake light wire brown ? Thanks
asked by: Jerry W
0
Expert Reply:
Hey Jerry, when installing the Roadmaster Brake Lite Relay part # RM-88400 the red wire runs to the running light circuit which is typically a brown wire. In the diagram it's being called the taillight circuit but that's same thing as running light.
expert reply by:
Jameson C
0
Wiring Diagram
(click to enlarge)
(click to enlarge)
Product Page this Question was Asked From
Roadmaster Brake-Lite Relay Kit for Towed Vehicles
- Flat Tow Brake System
- Brake Light Relay
- Roadmaster
more information >
Featured Help Information
Instructions
Continue Researching
- Search Results: hitch ball
- Search Results: diodes
- Search Results: roadmaster diodes
- Search Results: curt mounting bracket
- Search Results: trailer breakaway kit accessories and parts
- Search Results: rm643
- Search Results: 4 flat mounting bracket
- Video: Breaking Down the Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit
- Video: Checking Out the Pollak Connector Bracket for 4-, 5- and 6-Pole Trailer Connector Sockets
- Video: A Closer Look at the Curt Trailer Connector Adapter
- Video: Review of TowSmart Trailer Wiring - 4 Way Flat Trailer Connector With Wire Tester - TS84RR
- Video: Choosing the Right Tow Bar Wiring
- Video: RoadMaster BrakeMaster Second RV Kit for Hydraulic Brakes Review
- Video: Curt 2 to 3 Wire Tail Light Converter: The Breakdown
- Shop: Vehicle Tow Bar Wiring
- Shop: Trailer Wiring
- Q&A: Buzzing Noise from Vehicle to Vehicle Tail Light Converter Part # C56196
- Q&A: Is There a Coiled 5-Way to 5-Way Trailer Wiring Adapter
- Shop: Curt 4-Way Flat Trailer Connector w/ 60" Harness and Mounting Bracket
- Shop: Blue Ox 7-Wire to 6-Wire, Coiled Electrical Cord
- Shop: Pollak Connector Bracket for 4-, 5- and 6-Pole Trailer Connector Sockets
- Shop: Curt Tow Bar 7-Way to 6-Way Coiled Adapter Cord w/ 6-Way Socket - 7' Long
- Shop: Curt Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End - 48" Long
- Shop: Curt Mounting Bracket for 4-Pole Flat Trailer Connector
- Shop: Roadmaster Brite-Lite 3-to-2 Tail Light Converter for Towed Vehicles
- Article: Trailer Wiring Diagrams
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Shop: Trailer Hitch
- Q&A: What is the Difference Between a 4-Way and 7-Way Trailer Connector
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
Explore Expert Info
![Our Expert]()
on Flat Tow Brake System
on Flat Tow Brake System
Jerry W.
2/24/2026
Thank you for the information