Tekonsha T-One T-Connector Harness (Model 118599)

1. Introduction

This manual provides comprehensive instructions for the proper installation and operation of the Tekonsha T-One T-Connector Harness, Model 118599. This product is designed to provide a 4-way flat trailer wiring connection for specific Ford Explorer, Ford Taurus, and Lincoln MKS vehicle models, enabling trailer lighting functions without requiring modifications to the vehicle's existing wiring system.

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 exhaust components, sharp edges, and moving parts to prevent damage.
• Verify all trailer lights are functioning correctly after installation and before towing.
• If you are unsure about any step of the installation process, consult a qualified automotive technician.

3. Package Contents

The Tekonsha T-One T-Connector Harness kit includes the following components:

• T-One T-Connector Harness with ModuLite HD module
• 4-Way Flat Connector with cap
• Power wire (16 gauge bonded wire)
• Fuse holder and fuse
• Ring terminal
• Splice connectors
• Mounting screw
• Cable ties

Image 3.1: All components included in the Tekonsha T-One T-Connector Harness kit, featuring the main harness, ModuLite module, 4-way flat connector, power wire, fuse, and various installation accessories.

4. Setup and Installation

The Tekonsha T-One T-Connector Harness is designed for a straightforward, do-it-yourself installation without requiring special tools or splicing into vehicle wires. Follow these steps carefully:

4.1. Preparation

1. Gather Tools: You will need basic hand tools such as a screwdriver, wire strippers/crimpers, and possibly a test light.
2. Vehicle Access: Open the vehicle's trunk or tailgate and locate the access panels for the taillight assemblies. Remove these panels to expose the vehicle's wiring harness connectors.
3. Disconnect Battery: For safety, disconnect the negative terminal of the vehicle's battery.

4.2. Harness Connection

4. Locate Vehicle Connectors: Identify the vehicle's taillight wiring harness connectors. These are typically located behind the taillight assemblies.
5. Disconnect and Insert T-Connectors: Unplug the vehicle's wiring harness connector. Insert the corresponding T-One T-Connector into the vehicle's harness, ensuring a secure fit. The T-One connectors are designed to match the factory connectors, providing a 'factory' appearance.
6. Repeat for Both Sides: Connect the T-One harness to both the driver's side and passenger's side taillight wiring.

4.3. ModuLite HD Module Mounting

7. Mount Module: Find a secure, dry location within the vehicle's trunk or cargo area to mount the ModuLite HD module. Use the provided mounting screw or cable ties to secure it. Ensure the module is protected from moisture and physical damage.
8. Ground Connection: Connect the white wire from the ModuLite module to a clean, unpainted metal surface on the vehicle chassis to establish a proper ground. Use the provided ring terminal and mounting screw.

4.4. Power Connection

9. Route Power Wire: Route the black power wire from the ModuLite module to the vehicle's battery. Ensure the wire is routed safely, away from moving parts, exhaust, and sharp edges. Use cable ties to secure the wire along its path.
10. Install Fuse Holder: Near the battery, cut the power wire and install the provided fuse holder. Insert the fuse into the holder.
11. Connect to Battery: Connect the power wire from the fuse holder to the positive (+) terminal of the vehicle's battery using a suitable connector (not always included, may require a separate purchase depending on battery terminal type).

4.5. Final Steps

12. Secure 4-Way Flat Connector: Route the 4-way flat connector to an accessible location near the rear bumper, where it can be easily connected to a trailer. When not in use, store it in the cargo area or under the rear bumper, using the provided cap to protect the terminals.
13. Reconnect Battery: Reconnect the negative terminal of the vehicle's battery.
14. Test System: Before towing, perform a thorough test of all trailer lighting functions (turn signals, brake lights, running lights) with a connected trailer or a trailer light tester.

5. Operating Instructions

Once installed, operating the Tekonsha T-One T-Connector Harness is straightforward:

• Connect Trailer: When ready to tow, remove the protective cap from the 4-way flat connector and plug it into the corresponding connector on your trailer.
• Verify Lights: Always verify that all trailer lights (running lights, brake lights, left turn signal, right turn signal) are functioning correctly before driving.
• Disconnect Trailer: When not towing, disconnect the trailer's wiring harness from the vehicle's 4-way flat connector and replace the protective cap to prevent corrosion and damage.

6. Maintenance

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

• Inspect Connections: Periodically check all wiring connections for corrosion, fraying, or damage. Ensure the ground connection remains secure.
• Protect Connector: Always use the protective cap on the 4-way flat connector when not in use to shield it from dirt, moisture, and road debris.
• Clean Terminals: If terminals appear dirty or corroded, clean them with a wire brush and electrical contact cleaner.

7. Troubleshooting

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

8. Specifications

9. Warranty and Support

For warranty information and technical support, please refer to the official Tekonsha website or contact their customer service directly. Details regarding specific warranty periods and coverage are typically provided with the product packaging or on the manufacturer's official resources.