1. Introducció
This manual provides comprehensive instructions for the installation, operation, and maintenance of the Tekonsha T-One T-Connector Harness, Model 118685. This 4-way flat wiring harness is designed to provide a reliable electrical connection for trailer lighting on select Toyota Tacoma vehicles, simplifying the process by eliminating the need for cutting or splicing vehicle wires.
2. Informació de seguretat
Always prioritize safety during installation and operation. Failure to follow these instructions could result in property damage, injury, or death.
- Desconnecteu la bateria del vehicle: Before beginning any electrical work, disconnect the vehicle's negative battery terminal to prevent accidental short circuits.
- Utilitzeu equip de protecció: Utilitzeu l'equip de protecció individual adequat, com ara ulleres i guants de seguretat.
- Verificar la compatibilitat: Ensure this product is compatible with your specific vehicle make, model, and year before installation.
- Instal·lació professional: If you are unsure about any step, seek assistance from a qualified automotive technician.
- Cablejat segur: Properly route and secure all wiring to prevent chafing, pinching, or contact with hot or moving parts.
- Prova de connexions: After installation, thoroughly test all trailer lighting functions (turn signals, brake lights, tail lights) before towing.
3. Contingut del paquet
Verifiqueu que tots els components siguin presents abans de començar la instal·lació:
- Tekonsha 118685: T-One T-Connector Harness, 4-Way Flat
- Installation Hardware (e.g., zip ties, fuse, connectors, ground screw)

4. Configuració i instal·lació
The Tekonsha T-One T-Connector Harness is designed for a straightforward, plug-and-play installation. No cutting or splicing of vehicle wires is required.
4.1 Eines necessàries
- Basic hand tools (e.g., screwdriver, wrench)
- Wire crimpers (if using included terminals)
- Prova de llum o multímetre
- Dielectric grease (recommended)
4.2 Passos d'instal·lació
- Preparar el vehicle: Ensure the vehicle is turned off and the parking brake is engaged. Disconnect the negative battery terminal.
- Access Tail Light Wiring: Locate and remove the tail light assemblies on your Toyota Tacoma. This typically involves removing a few screws and carefully pulling the assembly away from the vehicle body.
- Locate Vehicle Harness Connector: Behind each tail light, identify the vehicle's existing wiring harness connector.
- Connect T-Connector: Unplug the vehicle's harness connector. Insert the corresponding ends of the T-One T-Connector into the vehicle's harness and the tail light assembly, ensuring a secure connection. Repeat for both sides of the vehicle.
- Mount ModuLite HD Module: Find a secure, dry location within the vehicle's rear cargo area or behind the bumper to mount the ModuLite HD module. Use the provided zip ties or screws.
- Route Power Wire: Route the power wire (typically red) from the ModuLite HD module to the vehicle's battery. Ensure the wire is protected from heat, sharp edges, and moving parts. Use the provided inline fuse holder near the battery connection.
- Connecteu el cable de terra: Connect the white ground wire from the ModuLite HD module to a clean, unpainted metal surface on the vehicle chassis using the provided ring terminal and screw.
- Cablejat segur: Use zip ties to secure all loose wiring, preventing it from hanging or interfering with other components.
- Reinstall Tail Lights: Reinstall the tail light assemblies.
- Torneu a connectar la bateria: Torneu a connectar el terminal negatiu de la bateria.
- Sistema de prova: Proceed to the "Operation" section to test all trailer lighting functions.
Note: For visual guidance, refer to the installation videos provided below for similar products. While not specific to this exact model, they demonstrate the general process.
4.3 Installation Video (Similar Product)
4.4 Additional Installation Video (Similar Product)
5. Funcionament
Once installed, the T-One T-Connector Harness provides a standard 4-way flat connector for your trailer's electrical system.
5.1 Connecting to a Trailer
- Ensure both the vehicle and trailer are off.
- Remove the dust cap from the 4-way flat connector on the T-One harness.
- Align the 4-way flat connector with the corresponding receptacle on your trailer and push firmly until fully seated.
- Secure any excess wiring to prevent dragging or damage.
5.2 Testing Trailer Lights
After connecting the trailer, perform the following tests:
- Llums posteriors: Turn on your vehicle's headlights. The trailer's tail lights should illuminate.
- Llums de fre: Press the vehicle's brake pedal. The trailer's brake lights should illuminate.
- Senyal de gir a l'esquerra: Activate the vehicle's left turn signal. The trailer's left turn signal should flash.
- Right Turn Signal: Activate the vehicle's right turn signal. The trailer's right turn signal should flash.
If any lights do not function correctly, refer to the "Troubleshooting" section.
6. Manteniment
Regular maintenance ensures the longevity and reliable performance of your T-One T-Connector Harness.
- Keep Connectors Clean: Periodically inspect the 4-way flat connector for dirt, corrosion, or debris. Clean with a wire brush or electrical contact cleaner if necessary.
- Aplicar greix dielèctric: Apply dielectric grease to the electrical contacts of the 4-way flat connector to protect against moisture and corrosion, especially before long-term storage or in harsh weather conditions.
- Inspeccioneu el cablejat: Regularly check all visible wiring for signs of wear, fraying, or damage. Ensure all connections are secure and zip ties are intact.
- Emmagatzema correctament: When not in use, keep the 4-way flat connector covered with its dust cap to protect it from elements. Store the harness in a dry location if it is removable.
7. Solució De Problemes
If you experience issues with your trailer lighting, follow these troubleshooting steps:
| Problema | Causa possible | Solució |
|---|---|---|
| No trailer lights function. |
|
|
| Specific trailer light (e.g., left turn) does not function. |
|
|
| Els llums parpellegen o són tènues. |
|
|
If problems persist after following these steps, consult a professional automotive technician.
8. Especificacions
| Característica | Detall |
|---|---|
| Marca | Tekonsha |
| Número de model | 118685 |
| Tipus de connector | T-one 4-way Flat |
| Material | Clorur de polivinil (PVC) |
| Dimensions de l'article (L x A x A) | 11 x 7.98 x 3.12 polzades |
| Pes de l'article | 1.75 lliures |
| Stop Light/Turn Signal Circuit Capacity | 5 Amp |
| Taillight Circuit Capacity | 7.5 Amp |
| UPC | 016118146103 |
9. Garantia i Suport
Specific warranty information for the Tekonsha T-One T-Connector Harness (Model 118685) is not provided in the available product data. For detailed warranty terms and conditions, or for technical support, please refer to the official Tekonsha weblloc web o contacteu directament amb el seu servei d'atenció al client.
You can often find support resources and contact information on the manufacturer's weblloc: www.tekonsha.com





