1. Introducción
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. Información de seguridad
- Desconecte siempre la batería del vehículo antes de comenzar cualquier instalación eléctrica para evitar descargas eléctricas o daños al sistema eléctrico del vehículo.
- Asegúrese de que todas las conexiones estén seguras y adecuadamente aisladas para evitar cortocircuitos.
- 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.
- Si no está seguro de algún paso del proceso de instalación, consulte con un técnico automotriz calificado.
3. Contenido del paquete
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)
- Portafusibles y fusible
- terminal de anillo
- Conectores de empalme
- Tornillo de montaje
- Bridas para cables

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. Configuración e instalación
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. Preparación
- Reunir herramientas: You will need basic hand tools such as a screwdriver, wire strippers/crimpers, and possibly a test light.
- Acceso de vehículos: 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.
- Desconecte la batería: For safety, disconnect the negative terminal of the vehicle's battery.
4.2. Conexión del arnés
- Locate Vehicle Connectors: Identifique los conectores del arnés de cableado de las luces traseras del vehículo. Normalmente se encuentran detrás de los conjuntos de luces traseras.
- 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.
- 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
- Módulo de montaje: 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.
- Conexión a tierra: 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. Conexión de alimentación
- Ruta del cable de alimentación: 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.
- Instalar portafusibles: Near the battery, cut the power wire and install the provided fuse holder. Insert the fuse into the holder.
- Conectar a la batería: 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. Pasos finales
- 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.
- Vuelva a conectar la batería: Vuelva a conectar el terminal negativo de la batería del vehículo.
- Sistema de prueba: 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. Instrucciones de funcionamiento
Once installed, operating the Tekonsha T-One T-Connector Harness is straightforward:
- Conectar tráiler: When ready to tow, remove the protective cap from the 4-way flat connector and plug it into the corresponding connector on your trailer.
- Verificar luces: 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. Mantenimiento
Minimal maintenance is required for the T-One T-Connector Harness:
- Inspeccionar las conexiones: Periodically check all wiring connections for corrosion, fraying, or damage. Ensure the ground connection remains secure.
- Proteger conector: Always use the protective cap on the 4-way flat connector when not in use to shield it from dirt, moisture, and road debris.
- Terminales limpias: If terminals appear dirty or corroded, clean them with a wire brush and electrical contact cleaner.
7. Solución de problemas
If you experience issues with your trailer lighting, consider the following troubleshooting steps:
| Problema | Posible causa | Solución |
|---|---|---|
| No trailer lights | Blown fuse in fuse holder | Verifique y reemplace el fusible. |
| No trailer lights | Conexiones sueltas o corroídas | Inspect all connections, clean if necessary, and ensure they are secure. |
| Specific trailer light not working | Faulty trailer bulb or wiring | Check the trailer's bulbs and wiring independently. |
| Luces parpadeantes | Mala conexión a tierra | Ensure the white ground wire is securely attached to a clean, unpainted metal surface. |
8. Especificaciones
| Característica | Especificación |
|---|---|
| Número de modelo | 118599 |
| Tipo de conector | 4-Way Flat |
| Capacidad del circuito de luces de freno y de señal de giro | 2.1 Amps |
| Capacidad del circuito de la luz trasera | 5.6 Amps |
| Wire Gauge | 16 Gauge bonded wire |
| Tipo de módulo | Upgraded circuit protected ModuLite HD module |
| Material | Cobre |
| Peso del artículo | 1.5 libras |
| Dimensiones del producto (L x An x Al) | 3.98 x 3.88 x 8.88 pulgadas |
9. Garantía y soporte
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.





