Tip for Finding Stoplight Circuit for 2021 Kia Sedona for Brake Controller Install
Updated 10/22/2025 | Published 03/27/2025 >
Products Featured in This Question
Question:
Hello, I am installing the Redarc brake controller, but I do not know what wire is the brake light for the red wire connection. I have a 2021 Kia Sedona Ex. How do I find this out? A NCV tester has not seemed to work. How do I find this information? Thank you,
asked by: Grant M
Expert Reply:
Hey Grant, did you test all of the tires that run to your stoplight circuit with your tester? If not, that is the place to check. Since you used a non contact tester and some say those aren't always reliable I would try again with a probing tester like our part # PTW2993. You will be looking for a circuit that only has voltage when the brakes are applied.
Another option is a universal stoplight switch like the part # RM-751000 which you'd install at the brake pedal and it will give you the stoplight circuit you need for the red wire of your controller.
Product Page this Question was Asked From
Redarc Tow-Pro Liberty Brake Controller w/ Universal Wiring Harness - Dash Knob - Proportional
- Trailer Brake Controller
- Proportional Controller
- Electric
- Electric over Hydraulic
- Splice-In
- Dash-Mounted Knob
- Behind-Dash
- Up to 2 Axles
- Indicator Lights
- Single Trailer Only
- Redarc
more information >
Featured Help Information
Instructions
Continue Researching
- Video: Trailer Brake Controller Installation - 2008 Kia Sedona
- Search Results: cover
- Search Results: weight distribution hitch
- Shop: Trailer Hitch
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Search Results: 7 pin wiring harness
- Q&A: How To Install a 7-Way Trailer Connector and Brake Controller On a 2017 Kia Sedona
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Article: 2 Steps for Finding the Right Weight Distribution Hitch Size
- Video: Set up: Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets on a 2014 Honda Odyssey
- Q&A: Is There Any Advantage in Using SumoSprings With Weight Distribution on a 2016 Toyota Tacoma
- Video: A Closer Look at the 30 amp. In-Line Circuit Breaker
- Video: Coil SumoSprings Custom Helper Springs for Coil Spring Suspension Spec Review
- Shop: Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector
- Q&A: Recommended Transmission Cooler for a 2017 Kia Sedona
- Q&A: Installation and Torque of 1-1/4 Inch Shank Hitch Ball onto Ball Mount
- Q&A: Locating The Correct Brake Switch Wire On A 2019 Kia Sorento
- Shop: Coil SumoSprings Custom Helper Springs for Coil Spring Suspension - Rear Axle
- Q&A: Easiest Brake Controller Solution for 2018 Kia Sedona
- Q&A: What is the Difference Between a 4-Way and 7-Way Trailer Connector
- Shop: Pollak Circuit Breaker - Cycling/Automatic Reset - 40 Amp - Straight Mount Bracket
- Shop: Single Pole 40 Amp Thermal Circuit Breaker - No Mounting Bracket
- Shop: Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets - Class IV - Efficient
- Shop: Coil SumoSprings Custom Helper Springs for Coil Spring Suspension - Front Axle
- Search Results: trailer hitch
- Article: Trailer Wiring Diagrams
- Video: How to Choose a Trailer Brake Controller
- Search Results: trailer wiring
- Video: Feature Breakdown: Universal Installation Kit for Trailer Brake Controller
- Search Results: trailer tires and wheels


Jameson C.
10/22/2025
Hey Grant, how did things go finding the correct brake light wire for your Sedona when hooking up the Redarc controller? Your results could really help others working through the same wiring step.