Trailer Brake Controller Install 2018 Mazda CX-9 Grand Touring
Question:
I need to connect the red wire from my Redarc Tow-Pro Brake Controller to my 2018 Mazda CX-9. Your ETBC7 instructions say the red wire must be spliced into the cold wire at the brake switch. Ive located the switch picture attached, which has 4 small gauge wires, red, blue, black, and green. Its difficult to reach, and so far I havent been able to unplug the wires from the switch. 1. Im unclear on how to test the wires to identify the cold one. Do you know from the colors which one it is? 2. Im assuming the blue wire splice from the ETBC7 is for 16-14 gauge wire, which will work for the brake controllers red wire. The wire on the switch looks like it may be 18 gauge wire. Will the blue splice connector work with such a small wire? 3. The Redarc instructions say the brake light terminal on some vehicles may provide a suitable connection for the red wire, but not necessarily for all vehicles. Do you know if the brake light terminal is a suitable option for my Mazda CX-9? Thank you.
asked by: Mark
Expert Reply:
Since you've got a few questions in here, in order to make sure everything is addressed clearly I'm going to list the answers to each of your numbered questions below.
1) You can test the wires using a Circuit Tester kit like # PTW2993 to determine which is the cold wire. Since auto manufacturers don't have a standard color they all use, it's tough to determine what is what on some manufacturers. The only way to truly know which wire is which on your vehicle is to test for power when the brake isn't pressed and when it is.
2) Joining 2 different gauge wires is not uncommon, especially on automobiles. The # ETBC7 uses 10 gauge wires, but you still should be able to connect it to the smaller gauge wire. You'd probably be best served to twist the 2 together to join them and then finish with electrical tape, but you may be able to use a butt connector. To use a butt connector, fold the smaller gauge wire over itself and insert it into one end of the butt connector; then insert the larger gauge wire into the other end and crimp both ends.
3) RedArc recommends checking with the vehicle manufacturer; usually if we've done an install on a specific vehicle we can tell you with certainty if the connection is going to be suitable for this application or not. Unfortunately we have not done an install with this specific brake controller on this vehicle, but I recommend tapping into the stop light switch like you're already looking to do. You should be able to do it this way without any issue.
Products Referenced in This Question
Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Accessories and Parts
- Trailer Brake Controller
- Installation Kits
- etrailer
more information >
Product Page this Question was Asked From
Pollak Heavy-Duty, 7-Pole, Round Pin Trailer Wiring Socket - Vehicle End
- Trailer Wiring
- Trailer Connectors
- Vehicle End Connector
- Plug Only
- 7 Round - Round
- Pollak
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Curt Echo Under-Dash Bluetooth Brake Controller w/ OneControl App - 1 to 4 Axles - Proportional
- Shop: Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Shop: Brake Controller
- Shop: Vehicle Air Mattress
- Q&A: Locating Brake Switch Wire on 2016 Mazda CX-9
- Q&A: Installation of Brake Controller on 2017 Mazda CX-5
- Shop: Suspension Enhancement
- Video: Choosing the Right Brake Controller
- Q&A: What is the Difference Between a 4-Way and 7-Way Trailer Connector
- Shop: Redarc Tow-Pro Liberty Brake Controller - Dash Knob - 1 to 2 Axles - Proportional
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Search Results: trailer brake controller
- Shop: Trailer Hitch
- Article: Trailer Wiring Diagrams
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Video: Tekonsha Prodigy P3 Trailer Brake Controller Review
- Search Results: brake controller
- Shop: Trailer Wiring
- Article: Brake Controller Installation: Starting from Scratch
- Q&A: My Vehicle has a 4-Pin Trailer Plug, but Trailer has 7-Pin Trailer Plug
- Search Results: etbc7
- Article: Towing a Trailer? Let's Talk About Brake Controllers
- Video: Choosing the Right Trailer Wiring
- Search Results: 90195
- Shop: Curt Echo Wireless Brake Controller - 7-Way Plug Mount w/ Bluetooth App - 1 to 2 Axle - Proportional
- Video: Redarc Tow-Pro Liberty Brake Controller Review RED24FR
- Shop: Gooseneck Hitch
- Article: How to Choose the Right Trailer Hitch Class
- Search Results: 90160
on Trailer Wiring
