Product Details
- Brand: Tekonsha
- Model: 118789 118144 20114
- Includes: T-One T-Connector Custom Harness, Mounting Bracket, 4-Flat Car End Tester
Compatibility Chart
Description
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Trailer Wiring and Bracket w/ Light Tester For 18-23 BMW X2 Plug & Play 4-Flat Harness Install Notes
Installation Instructions for T-One® T-Connector for BMW X2
Part Numbers:
- 118789
Tools Required:
- Trim Panel Remover
- 10mm Socket & Ratchet or 10mm Wrench
- Drill (3/32” Drill Bit)
- 1/4” Socket
- Wire Crimpers
- Wire Cutters
- Phillips Head Screwdriver
- Test Probe
Step-by-Step Instructions:
-
Remove the Taillight Assemblies:
- Open the tailgate and carefully pry the black taillight trim cover using a trim panel remover to expose the two 10mm taillight fasteners on the driver’s side.
- Remove the two 10mm screws on both driver and passenger sides.
- Gently pull the taillights away from the vehicle, being cautious not to damage the alignment pins. Set the taillight housings aside.
-
Locate the Taillight Wiring Harness:
- On both sides of the vehicle, locate the taillight wiring harness.
- Disconnect the wiring connectors carefully, ensuring not to break the locking tabs. Ensure all connectors are clean and free of dirt.
-
Mount the T-One® Black Box:
- Determine a suitable mounting point behind the rear bumper fascia on the driver’s side.
- Mount the black box module using the provided double-sided tape.
- Ensure the trailer wire harness has adequate length to reach this point.
Warning: Mount the module with the epoxy side facing downward to prevent water accumulation.
-
Connect the Driver-Side T-Connector:
- Route the T-Connector end with the yellow wires through the bumper and vehicle body into the driver-side taillight pocket.
- Insert the T-Connector end with the yellow wire between the driver-side taillight socket and the vehicle wiring harness.
-
Route the Passenger-Side T-Connector:
- Route the T-Connector end with the green wire underneath the bumper to the passenger side.
- Insert the green wire end through the passenger-side opening and connect it between the taillight socket and the vehicle wiring harness.
- Avoid hot pipes, heat shields, or areas that may pinch or damage the wires.
-
Ground the White Wire:
- Locate a suitable grounding point near the connector, such as the vehicle frame or crossmember.
- Clean the area of dirt and rustproofing.
- Drill a 3/32” hole and secure the white wire using the provided eyelet and screw.
Caution: Verify what is behind the surface before drilling to prevent damage or injury.
-
Route the Power Wire:
- Locate the black 12-gauge power wire from the T-One® Connector box.
- Attach the provided black wire and route it along the exterior frame or follow existing wiring to the vehicle’s battery.
- Avoid areas that may pinch, cut, or break the wire.
-
Connect to the Vehicle Battery:
- Disconnect the Negative (-) battery cable.
- Remove the fuse from the yellow fuse holder and attach the ring terminal to the Positive (+) battery cable.
- Connect the other end of the fuse holder to the black 12-gauge wire using the yellow butt connector.
Warning: Follow all warnings and cautions printed on the tow vehicle’s battery.
-
Reconnect the Battery and Test:
- Reconnect the Negative (-) battery cable.
- Insert the 15-amp fuse into the fuse holder.
- Test the installation using a test light or trailer.
-
Secure the Wiring Harness:
- Use the provided cable ties to secure the harness, avoiding areas that may pinch, cut, or melt the wires.
-
Reassemble the Vehicle:
- Replace all panels and components removed during installation, ensuring no wires are pinched or damaged.
-
Store the 4-Flat Connector:
- Route the 4-flat harness underneath and to the center of the vehicle.
- Mount the 4-flat end in an accessible location using a bracket or electrical box (not included).
Safety Notes:
- Overloading circuits can cause fires. Do not exceed stated product ratings or vehicle manufacturer specifications.
- Always wear safety glasses and follow all safety precautions during installation.
Manufacturer Notes:
- Refer to the vehicle owner’s manual and the instruction sheet for additional details.
- Store these instructions for future reference.
Installation Instructions for T-One® T-Connector for Various Vehicles
Part Numbers:
- 118789
Tools Required:
- Trim Panel Remover
- 10mm Socket & Ratchet or 10mm Wrench
- Drill (3/32” Drill Bit)
- 1/4” Socket
- Wire Crimpers
- Wire Cutters
- Phillips Head Screwdriver
- Test Probe
Step-by-Step Instructions:
-
Remove the Taillight Assemblies:
- Open the tailgate and carefully pry the black taillight trim cover using a trim panel remover to expose the two 10mm taillight fasteners on the driver’s side.
- Remove the two 10mm screws on both driver and passenger sides.
- Gently pull the taillights away from the vehicle, being cautious not to damage the alignment pins. Set the taillight housings aside.
-
Locate the Taillight Wiring Harness:
- On both sides of the vehicle, locate the taillight wiring harness.
- Disconnect the wiring connectors carefully, ensuring not to break the locking tabs. Ensure all connectors are clean and free of dirt.
-
Mount the T-One® Black Box:
- Determine a suitable mounting point behind the rear bumper fascia on the driver’s side.
- Mount the black box module using the provided double-sided tape.
- Ensure the trailer wire harness has adequate length to reach this point.
Warning: Mount the module with the epoxy side facing downward to prevent water accumulation.
-
Connect the Driver-Side T-Connector:
- Route the T-Connector end with the yellow wires through the bumper and vehicle body into the driver-side taillight pocket.
- Insert the T-Connector end with the yellow wire between the driver-side taillight socket and the vehicle wiring harness.
-
Route the Passenger-Side T-Connector:
- Route the T-Connector end with the green wire underneath the bumper to the passenger side.
- Insert the green wire end through the passenger-side opening and connect it between the taillight socket and the vehicle wiring harness.
- Avoid hot pipes, heat shields, or areas that may pinch or damage the wires.
-
Ground the White Wire:
- Locate a suitable grounding point near the connector, such as the vehicle frame or crossmember.
- Clean the area of dirt and rustproofing.
- Drill a 3/32” hole and secure the white wire using the provided eyelet and screw.
Caution: Verify what is behind the surface before drilling to prevent damage or injury.
-
Route the Power Wire:
- Locate the black 12-gauge power wire from the T-One® Connector box.
- Attach the provided black wire and route it along the exterior frame or follow existing wiring to the vehicle’s battery.
- Avoid areas that may pinch, cut, or break the wire.
-
Connect to the Vehicle Battery:
- Disconnect the Negative (-) battery cable.
- Remove the fuse from the yellow fuse holder and attach the ring terminal to the Positive (+) battery cable.
- Connect the other end of the fuse holder to the black 12-gauge wire using the yellow butt connector.
Warning: Follow all warnings and cautions printed on the tow vehicle’s battery.
-
Reconnect the Battery and Test:
- Reconnect the Negative (-) battery cable.
- Insert the 15-amp fuse into the fuse holder.
- Test the installation using a test light or trailer.
-
Secure the Wiring Harness:
- Use the provided cable ties to secure the harness, avoiding areas that may pinch, cut, or melt the wires.
-
Reassemble the Vehicle:
- Replace all panels and components removed during installation, ensuring no wires are pinched or damaged.
-
Store the 4-Flat Connector:
- Route the 4-flat harness underneath and to the center of the vehicle.
- Mount the 4-flat end in an accessible location using a bracket or electrical box (not included).
Safety Notes:
- Overloading circuits can cause fires. Do not exceed stated product ratings or vehicle manufacturer specifications.
- Always wear safety glasses and follow all safety precautions during installation.
Attention: This is a summary of the installation procedure. For complete installation instructions, including diagrams and detailed information from the manufacturer, please download the full installation PDF.
Manufacturer Notes:
- Refer to the vehicle owner’s manual and the instruction sheet for additional details.
- Store these instructions for future reference.
Warranty Information:
- For complete warranty instructions, please download the full installation PDF.
For technical support and assistance, our team of experts is available to help. You can reach our tech support by visiting www.trailerjacks.com or calling 877-869-6690.