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2022 - 2025 BMW X3
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Tekonsha T-One connector (also referred to as T-Connector) wiring harnesses are the fastest and easiest way to add an electrical connector to the back of your vehicle. These connectors are used to link the wiring from your vehicle to the trailer when towing. Tekonsha T-One connectors feature custom designs to fit each vehicle make and model based on manufacturer specifications. Plus, the Plug & Play connectors on the end of the wires make it easy to install. No cutting or splicing!
Tekonsha offers the largest, most complete line of T-One connectors. To install a Tekonsha T-One wiring harness, simply locate your vehicle's wiring harness connector typically behind the vehicle taillight - unplug the connection and insert the T-Connector into the vehicle's harness. It's that easy! So what are you waiting for? Hit the road with the peace of mind only Tekonsha can provide. Life's a Journey. Stop Often.
| BRAND: | TEKONSHA |
| PART NUMBER: | 118879 |
| WARRANTY: | LIMITED 1 YEAR WARRANTY |
| WEIGHT: | 1.5 LBS |
| UNIVERSAL OR SPECIFIC FIT: | SPECIFIC |
| CIRCUIT PROTECTED: | YES |
| HARNESS TYPE: | MALE FEMALE |
| TERMINAL QUANTITY: | 4 |
| WIRE COLORS: | BROWN, GREEN, WHITE, YELLOW |
| WIRE QUANTITY: | 4 |
| WIRE GAUGE: | 18 AWG, 0.85 AVSS |
| POWER LEAD REQUIRED: | YES |
| ELECTRICAL SYSTEM TYPE: | 2-WIRE SYSTEM |
| HARDWARE INCLUDED: | YES |
Tekonsha is a leading manufacturer of electronic trailer brake controllers, pioneering the category in the 1970s. The lineup spans proportional units such as the Prodigy P3 and Prodigy iD, time-delayed controllers, the wireless Prodigy RF, plus vehicle-specific wiring harnesses, adapters and trailer brake components engineered for smooth, predictable stopping at any speed.
Tekonsha Engineering Company began in 1964 building RV steps and mirrors. Within a few years it had found its real calling, and by the 1970s Tekonsha was pioneering the manufacture of electronic trailer brake controllers, the product category that still defines the brand. More than half a century later it remains the reference name in trailer braking and is part of the Horizon Global group alongside Reese, Draw-Tite, Fulton, Bulldog and Wesbar.
A brake controller is the component that tells a trailer's electric brakes how hard to work and when, and getting that right is the difference between a controlled stop and a shove from behind. Tekonsha builds both major types. Proportional controllers use an internal accelerometer to sense how quickly the tow vehicle is slowing and apply trailer braking to match, so light braking stays light and hard braking is immediate. Time-delayed controllers ramp to a preset output over a fixed interval, a simpler and more economical approach that suits occasional towing.
The current brake controller range covers most of that ground. The Prodigy iD pairs with a phone through Tekonsha's EDGE technology for setup and monitoring, the P3 offers storable settings for multiple trailers and a trilingual colour LED display, the Prodigy P2 adds a dimmable display and boost mode for heavier loads, and the Voyager keeps operation simple and dependable. The Prodigy RF mounts to the trailer itself and controls wirelessly, which suits rental fleets and drivers who swap tow vehicles.
Installation is supported by vehicle-specific brake control harnesses that plug into a factory connector rather than requiring cut-and-splice wiring, along with mounting brackets and adapters. Matched controller bundles pair a unit with the correct harness. Products are tested to meet and often exceed published industry standards.
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The 2022-2023 BMW X3 Tekonsha Plug & Play T-Connector Adapter Trailer Wiring 118879 (Part #TK118879) fits 2022-2025 BMW X3 models. The 2025 model year is the last year covered by this part number. For newer models, check for an updated version.
The 2022-2023 BMW X3 Tekonsha Plug & Play T-Connector Adapter Trailer Wiring 118879 (Part #TK118879) fits the following vehicles: 2022-2025 BMW X3. Always verify your specific year, make, and model before ordering.
Yes, the 2022-2023 BMW X3 Tekonsha Plug & Play T-Connector Adapter Trailer Wiring 118879 (Part #TK118879) is designed to fit the 2022-2025 BMW X3.
The 2022-2023 BMW X3 Tekonsha Plug & Play T-Connector Adapter Trailer Wiring 118879 (Part #TK118879) Drilling is required for installation. Basic hand tools are typically all you need.
The T-One® Connector (part number 118879-037) is a vehicle wiring connector system that integrates with your vehicle's tail light wiring to enable trailer lighting control. It consists of a black box module, wiring harnesses with colour-coded wires (yellow, green, white, and black), and a 4-Flat connector for trailer use. The system allows your vehicle to communicate lighting signals to a connected trailer.
You will need: Trim Panel Remover, #2 Philips Screwdriver, Flat Screwdriver, 10mm Socket or wrench, Drill with 3/32" Drill Bit, Wire Crimpers, Wire Cutters, and Test-probe. These tools are required to remove panels, disconnect wiring, drill if needed, crimp connections, and test the installation.
The kit includes: a black box module, colour-coded wiring harnesses (yellow, green, white, and black wires), double-sided tape for mounting the black box, cable ties for securing the harness, yellow butt connectors for wire connections, a yellow fuse holder with a 15 amp fuse, and ring terminals. A 4-Flat connector is also included for storage in the rear cargo area when not in use.
Yes. You must disconnect the vehicle's Negative (−) battery cable before making power connections. This is done in Step 11 before connecting the fuse holder to the positive battery cable. The negative cable is reconnected in Step 12 after all power connections are complete.
You must remove: the privacy screen (if installed), rear side cargo panels from both driver's and passenger's sides, cargo floor covering, and any trim panels required to access the driver's side trim panel opening where the black box module will be mounted. The felt liner covering the battery compartment must also be removed. Take care not to break locking tabs on cargo panels during removal.
The black box module is mounted on the driver's side behind the trim panel opening using the double-sided tape provided in the hardware kit. The remainder of the harness is secured with cable ties to prevent damage or rattling, taking care to avoid areas that could cut or pinch the wire.
1. On the driver's side, insert the T-One® Connector end with the yellow wire between the mating vehicle wiring connectors and lock into place, ensuring locking tabs are fully engaged. 2. On the passenger's side, insert the T-One® Connector end with the green wire between the mating vehicle wiring connectors and lock into place. Both connections must be fully inserted with locking tabs secure to avoid damage.
The harness contains four wires: Yellow wire (driver's side tail light connection), Green wire (passenger's side tail light connection), Black 12 ga. wire (12-volt power connection to the positive battery terminal via the fuse holder), and White 14 ga. wire (ground connection to the negative battery terminal). Each wire has a specific routing and connection point as detailed in the installation steps.
The black 12 ga. power wire is routed from the T-One® black box to the battery compartment. It is connected to the black power wire on the black box using a yellow butt connector (provided). The wire then connects to the positive (+) battery cable through a fuse holder with a 15 amp fuse. The fuse holder is attached to the positive battery cable using a ring terminal after the fuse holder wire is cut.
The white 14 ga. ground wire is routed from the T-One® black box under the driver's side metal cargo rails to the battery compartment. It is connected to the negative (−) battery terminal using a ring terminal and a 10mm socket or wrench. This connection must be made after the negative battery cable is reconnected.
A 15 amp fuse is used. It is installed in the yellow fuse holder provided in the hardware kit. The fuse holder is connected between the black 12 ga. power wire and the vehicle's positive (+) battery cable. The fuse is installed in Step 13 after all other connections are complete.
Route the green wire end through the opening and under the metal cargo hook rails, along the vehicle's battery, and up through the opening under the passenger's cargo rail. Route the white 14 ga. ground wire and black 12 ga. power wire under the driver's side metal cargo rails to the battery compartment. Avoid routing wires through hot pipes, heat shields, the fuel tank, or any other points that may pinch or break the wire. Use cable ties to secure the harness and prevent rattling.
Always wear safety glasses during installation. Read and follow all warnings and cautions printed on the vehicle's battery before making electrical connections. Do not exceed the lower of the towing manufacturer's rating (including in your vehicle owner's manual) or the specific amperage ratings stated on the product. Avoid pinching or cutting wires when reinstalling trim panels. Do not damage locking tabs on connectors. All connections must be complete for the T-One® Connector to function properly.
Test and verify the installation with a test light or trailer once installed. For the initial test, reset the vehicle electrical system by temporarily removing the key from the ignition. Use a test-probe (included in required tools) to verify proper connections. Ensure all connections are complete and secure before testing.
Reinstall all plastic trim panels, floor covering, and other items that were removed during installation, being careful not to pinch or cut the wires. Verify that all connections are secure and complete. Test the installation with a test light or trailer. Reset the vehicle electrical system by temporarily removing the ignition key for the initial test. Store the 4-Flat connector in the rear cargo area when not in use.
The manual does not specify a maximum amperage rating for the product itself. However, you must not exceed the lower of: the towing manufacturer's rating (including the rating in your vehicle owner's manual) or the specific amperage ratings stated on the product. A 15 amp fuse is installed as part of the system. Refer to your vehicle owner's manual and the product documentation for specific amperage limits.
Yes, disconnect the Negative (−) battery cable before making power connections in Step 11. Reconnect it after all power connections are complete in Step 12.
A 15 amp fuse is installed in the yellow fuse holder provided. It protects the black 12 ga. power wire connection to the vehicle's positive battery terminal.
Do not exceed the lower of the towing manufacturer's rating or the specific amperage ratings stated on the product. Overloading circuits can cause fires. Wear safety glasses during installation and avoid routing wires through hot pipes, heat shields, or the fuel tank.
Verify that all connections are complete and secure. Check that the 15 amp fuse is installed in the fuse holder. Ensure the black power wire is connected to the positive battery terminal and the white ground wire is connected to the negative battery terminal. Test the installation with a test light or trailer. Reset the vehicle electrical system by temporarily removing the ignition key. If the system still does not function, verify that the yellow and green connector ends are fully inserted into the vehicle tail light connectors with locking tabs engaged.
Ensure you are inserting the connector ends fully between the mating vehicle wiring connectors. The locking tabs must engage completely. Be careful not to damage the locking tabs during insertion. If the tabs are damaged, the connectors will not lock properly and the system will not function. Do not force the connectors; they should slide in smoothly until the locking tabs engage.
1 compatible vehicles
| Year | Make & Model | Notes |
|---|---|---|
| 2022 - 2025 | BMW X3 | Tow Harness T: Connector Assembly Drilling Required Install Time is 60 minutes |
George
Ordered online. Shipment arrived on time and with all the correct parts. Great customer service and friendly staff. Also, pricing was great!
May 22, 2023
