Why Do Some Trailer Wiring Harnesses Have Wire that Runs to Vehicle Battery
Published 10/04/2018 >
Question:
Hi. I am planning to tow a trailer without any brake. Do I need to connect the wire from the trailer wiring harness to the cars battery for the running, signal, and brake lights to work? Thank you.
asked by: VP
Helpful Expert Reply:
Not all vehicles can handle the additional amperage draw of the trailer taillights on the vehicle taillight circuits. Those vehicles need setup that draws power from the battery. Some vehicles have higher rated circuits that can handle this, and others need to have the power drawn straight from the battery to protect the taillight circuits. So the connection has to be made to the vehicle battery otherwise the harness will not work.
That said, if you have a 2005 Toyota Matrix like you referenced the Curt trailer wiring harness part # C55522 does not require a power wire ran to the battery.
Product Page this Question was Asked From
Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Hidden
- CURT
more information >
Featured Help Information
Instructions
Continue Researching
- Shop: Trailer Hitch
- Shop: Curt Trailer Hitch Receiver - Custom Fit - Class III - 2"
- Q&A: Trailer Hitch and Wiring for a 2005 Toyota Matrix
- Search Results: single bike rack
- Video: Feature Breakdown: Replacement Endcap for Swagman XC and XTC Series Bike Carriers
- Video: Beginner’s Guide to Installing the Swagman Contour Kayak Roof Rack w/ Tie-Downs on a 2022 Kia Forte
- Shop: Trailer Wiring
- Video: Curt T-Connector Vehicle Wiring Harness Review C56040
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Search Results: trailer hitch
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Shop: Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector
- Video: Curt Powered Tail Light Converter Installation - 2023 Kia Telluride
- Article: Trailer Wiring Diagrams
- Search Results: trailer wiring
- Q&A: What is the Difference Between a 4-Way and 7-Way Trailer Connector
- Shop: etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class III - 2"
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Video: The Low-Down on the Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector
- Shop: Suspension Enhancement
- Q&A: Lug Nut Torque Chart for Trailer Wheels
- Article: How to Choose the Right Trailer Hitch Class
- Search Results: trailer tires and wheels
- Q&A: Recommended Bike Rack and Dual Hitch Adapter for Carrying E-Bikes While Flat Towing
- Shop: Brake Controller
- Article: How to Measure for Trailer Hitch Drop
- Video: Feature Breakdown: Universal Installation Kit for Trailer Brake Controller
- Search Results: trailer lights
- Shop: Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Shop: Base Plate for Tow Bar

