Tekonsha T-One® T-Connector Harness (Model 118756) Instruction Manual

1. Introduction

This manual provides detailed instructions for the proper installation, operation, and maintenance of the Tekonsha T-One® T-Connector Harness, Model 118756. This product is designed to provide a 4-way flat trailer wiring connection for select Toyota C-HR vehicles, enabling trailer lighting functions without cutting or splicing vehicle wires.

2. Safety Information

• Always disconnect the vehicle's battery before beginning any electrical installation to prevent electrical shock or damage to the vehicle's electrical system.
• Ensure all connections are secure and properly insulated to prevent short circuits.
• Route wiring away from hot surfaces, sharp edges, and moving parts to prevent damage.
• Verify proper function of all trailer lights before towing.
• If you are unsure about any step of the installation process, consult a qualified automotive technician.

3. Package Contents

Verify that all components are present before beginning installation:

• Tekonsha T-One® T-Connector Harness with integrated control module
• 4-Way Flat Connector
• Power wire with fuse holder and fuse
• Ground wire with ring terminal
• Assorted zip ties
• Butt connectors

4. Setup and Installation

The Tekonsha T-One® T-Connector Harness is designed for a "Plug & Play" installation, requiring no cutting, splicing, or taping of your vehicle's wires. The installation process typically involves accessing the vehicle's taillight wiring harness.

1. Prepare Vehicle: Ensure the vehicle is turned off and the parking brake is engaged. Disconnect the negative terminal of the vehicle's battery.
2. Access Taillight Wiring: Depending on your Toyota C-HR model, you may need to remove interior trim panels or access panels in the trunk or cargo area to reach the taillight wiring harness connectors. Refer to your vehicle's owner's manual for specific panel removal instructions.
3. Locate Vehicle Harness: Identify the vehicle's taillight wiring harness connectors. These are typically located behind the taillight assemblies.
4. Connect T-Connectors: Unplug the vehicle's existing taillight harness connector. Insert the corresponding Tekonsha T-Connector into the vehicle's harness, ensuring a secure connection. Then, plug the vehicle's original harness into the other end of the Tekonsha T-Connector. Repeat this process for both sides of the vehicle if applicable.
5. Mount Control Module: Find a secure, dry location within the vehicle's cargo area or behind the trim panels to mount the control module. Use the provided zip ties or double-sided tape (not included) to secure it, ensuring it is away from moving parts or areas prone to moisture.
6. Connect Power Wire: Route the power wire from the control module to the vehicle's battery. This may involve routing it through the vehicle's interior and firewall. Connect the fuse holder in-line near the battery, but do not insert the fuse until all connections are complete. Connect the power wire to the positive terminal of the battery.
7. Connect Ground Wire: Connect the white ground wire from the control module to a clean, unpainted metal surface on the vehicle's chassis using the provided ring terminal and a self-tapping screw. Ensure a good electrical ground.
8. Route 4-Way Flat Connector: Route the 4-way flat connector to the exterior of the vehicle, typically near the trailer hitch. Secure it using zip ties, ensuring it is protected from road debris and heat.
9. Final Checks: Reconnect the vehicle's battery. Insert the fuse into the fuse holder. Test all trailer light functions (turn signals, brake lights, running lights) with a trailer or a trailer light tester before reassembling any removed trim panels.

5. Operating Instructions

Once installed, the Tekonsha T-One® T-Connector Harness provides a standard 4-way flat connector for your trailer. To operate:

• Connect your trailer's 4-way flat plug to the vehicle's 4-way flat connector.
• Ensure the connection is secure and free from dirt or corrosion.
• Verify that all trailer lights (running lights, turn signals, brake lights) are functioning correctly before driving.
• When not in use, protect the 4-way flat connector with a dust cap (if provided or purchased separately) to prevent corrosion.

6. Maintenance

Minimal maintenance is required for the T-One® T-Connector Harness:

• Periodically inspect the 4-way flat connector for dirt, corrosion, or damage. Clean with electrical contact cleaner if necessary.
• Check all wiring for signs of wear, fraying, or loose connections, especially where wires pass through grommets or along the chassis.
• Ensure the control module remains securely mounted in a dry location.

7. Troubleshooting

If you experience issues with your trailer lights, consider the following troubleshooting steps:

• No Trailer Lights:
  • Check the fuse in the in-line fuse holder connected to the vehicle's battery. Replace if blown.
  • Ensure the vehicle's battery is properly reconnected and charged.
  • Verify all T-Connector connections are fully seated and secure.
  • Check the ground wire connection for corrosion or looseness. Ensure it is connected to a clean, unpainted metal surface.
  • Inspect the 4-way flat connector for dirt, corrosion, or bent pins.
• Specific Trailer Light Not Working (e.g., only turn signals, no brake lights):
  • Check the corresponding bulb on the trailer.
  • Inspect the wiring on the trailer itself for damage or loose connections.
  • Verify the vehicle's taillights are functioning correctly.
• Fuses Blow Repeatedly: This indicates a short circuit. Carefully inspect all wiring for pinched, cut, or exposed wires. Ensure the control module is not damaged.

If troubleshooting steps do not resolve the issue, contact Tekonsha customer support or a qualified automotive electrician.

8. Specifications

9. Warranty and Support

Tekonsha products are manufactured to high-quality standards. For specific warranty information, please refer to the documentation included with your purchase or visit the official Tekonsha website. For technical assistance or support, please contact Tekonsha customer service.

Tekonsha Website: www.tekonsha.com