Introduction
The CURT 55379 Vehicle-Side Custom 4-Pin Trailer Wiring Harness is designed to provide a standard, universal trailer wiring connection for select Toyota Pickup Trucks and Tacoma models. This plug-and-play electrical device connects directly into your vehicle's electrical system, eliminating the need for cutting, splicing, or soldering during installation. It ensures proper functionality of tail lights, brake lights, and turn signals on your trailer.
Key Features:
- Plugs into vehicle tail light assembly to provide a 4-way flat socket.
- Simple plug-and-play design eliminates the need for cutting or splicing.
- 4-way flat output connects tail lights, brake lights and turn signals.
- Equipped with tail light converter for vehicle-trailer compatibility.
- Constructed with SMT circuitry for better performance and durability.
What's in the Box
The CURT 55379 wiring harness package includes the following components:
- Custom Wiring Harness with 4-way flat connector
- Dust Cover for 4-way flat connector
- Installation Hardware (e.g., zip ties, screw for ground wire)
- Instruction Sheet (CME-P183-RA)
Image: Contents of the CURT 55379 wiring harness package, showing the harness, zip ties, a screw, and the instruction sheet.
Image: The CURT Custom Wiring Harness as it appears in its retail packaging.
Setup and Installation
This section provides general guidance for installing the CURT 55379 Vehicle-Side Custom 4-Pin Trailer Wiring Harness. Always refer to the specific instructions included with your product for detailed, vehicle-specific steps.
General Installation Steps:
- Preparation: Ensure your vehicle is turned off and the parking brake is engaged. It is recommended to disconnect the negative battery terminal before starting electrical work.
- Locate Tail Light Wiring: Access the vehicle's tail light wiring. This typically involves removing the tail light assemblies.
- Connect T-Connectors: The CURT 55379 harness features vehicle-specific T-connectors. Plug these connectors directly into the corresponding sockets of your vehicle's tail light wiring. This is a plug-and-play process that avoids cutting or splicing.
Image: A representative image illustrating the plug-and-play connectors and the standard 4-pin trailer wiring output of the harness.
Image: A person's hands connecting a vehicle-specific plug-and-play connector into the vehicle's existing wiring harness, typically behind the tail light assembly.
- Ground the Wiring: Secure the white ground wire to a clean, unpainted metal surface on the vehicle's frame using the provided screw. A good ground connection is crucial for proper operation.
- Route the 4-Way Flat Connector: Route the 4-way flat connector to the exterior of the vehicle, typically near the trailer hitch. Ensure the wiring is secured using zip ties to prevent it from dangling or being damaged by road debris.
- Secure the Module: If your harness includes a converter module, mount it in a secure, dry location within the vehicle's rear compartment or under the vehicle, away from excessive heat or moisture.
- Test the Connection: Reconnect the vehicle battery. Use a trailer or a trailer light tester to verify that all tail lights, brake lights, and turn signals function correctly.
Video: An overview of CURT towing products, including demonstrations of wiring harness installations and usage scenarios. This video provides context on how CURT wiring harnesses integrate with various towing setups.
Operating Instructions
Once installed, the CURT 55379 wiring harness provides a reliable 4-way flat connection for your trailer. Follow these steps for proper operation:
- Connecting to Trailer:
- Remove the dust cover from the vehicle's 4-way flat connector.
- Align the trailer's 4-way flat connector with the vehicle's connector and push firmly until fully seated.
- Ensure the connection is secure and free from debris.
Image: A close-up view of a 4-way flat connector, illustrating the male and female ends ready for connection. The trailer end is not included with the harness.
- Dust Cover Usage: When not towing, always place the included dust cover over the vehicle's 4-way flat connector to protect it from dirt, moisture, and corrosion.
Image: A person's hands demonstrating the placement of the dust cover over the 4-way flat trailer wiring connector to protect it when not in use.
- Verify Lights: Before each trip, perform a quick check to ensure all trailer lights (tail lights, brake lights, turn signals) are functioning correctly.
- Vehicle Running: For optimal performance and to ensure sufficient voltage, especially for trailer lights, ensure the vehicle's engine is running when testing or operating trailer lights.
Maintenance
Regular maintenance helps ensure the longevity and reliable performance of your CURT wiring harness.
- Inspect Connections: Periodically check all wiring connections for corrosion, fraying, or damage. Ensure the ground wire remains securely attached to a clean metal surface.
- Clean Connectors: Keep the 4-way flat connector clean and free of dirt, dust, and moisture. Use electrical contact cleaner if necessary.
- Apply Dielectric Grease: Apply dielectric grease to the electrical contacts of the 4-way flat connector to prevent corrosion and improve conductivity, especially in humid or wet conditions.
- Secure Wiring: Ensure all wiring is properly secured with zip ties and not dangling, which could lead to damage from road debris or snagging.
- Dust Cover: Always use the dust cover when the harness is not connected to a trailer.
Troubleshooting
If you experience issues with your trailer lights, follow these troubleshooting steps:
If lights function intermittently or not at all:
- Check Vehicle Fuses: Verify that the vehicle's tail light and brake light fuses are intact and not blown.
- Inspect Trailer Bulbs: Ensure all trailer light bulbs are in good condition and properly seated.
- Check Connections: Disconnect and reconnect the 4-way flat connector, ensuring a firm and clean connection.
- Verify Ground Wire: Confirm the white ground wire is securely attached to a clean, unpainted metal surface on the vehicle frame. A poor ground is a common cause of electrical issues.
- Test with Another Trailer/Tester: If possible, test the vehicle's wiring harness with a different trailer or a dedicated trailer light tester to isolate whether the issue is with the vehicle's wiring or the trailer's wiring.
- Circuit Protection: The harness includes a circuit-protected converter system. In case of a short or overload, the module is designed to shut down the circuit to protect the vehicle. If trailer lights are not working, but vehicle lights are, the module may have temporarily shut off. It should reset after a few seconds.
Image: A close-up of the instruction sheet (CME-P183-RA) detailing troubleshooting steps for the circuit protected converter systems, including checks for fuses, ground, and trailer bulbs.
Specifications
| Feature | Detail |
|---|---|
| Brand | CURT |
| Model Number | 55379 |
| Connector Type | 4-pin Flat |
| Vehicle Compatibility | Select Toyota Pickup Trucks, Tacoma |
| Material | Plastic |
| Item Dimensions (L x W x H) | 9 x 4 x 3 inches |
| Circuitry | SMT (Surface Mount Technology) |
| Included Components | Custom Wiring, Dust Cover |
Warranty and Support
The CURT 55379 Vehicle-Side Custom 4-Pin Trailer Wiring Harness comes with a 1 Year Limited Manufacturer Warranty. For warranty claims, technical support, or further assistance, please contact CURT customer service directly. Refer to the product packaging or the official CURT website for the most current contact information.
For additional resources and product information, you may visit the CURT Store on Amazon. You can also find the official user manual in PDF format here.
