Our in-house experts typically reply within one business day.
Tekonsha
Verify Fitment
Select your vehicle to confirm this part fits.
2017 - 2018 Mercedes-Benz GLC250
Confirmed to Fit
2016 - 2024 Mercedes-Benz GLC300
Confirmed to Fit
2018 - 2020 Mercedes-Benz GLC350e
Confirmed to Fit
2017 - 2024 Mercedes-Benz GLC43 AMG
Confirmed to Fit
2018 - 2021 Mercedes-Benz GLC63 AMG
Confirmed to Fit
2018 - 2021 Mercedes-Benz GLC63 AMG S
Confirmed to Fit
Always the correct part
We know our products
Quality Products
Free Shipping!
Always the correct part
We know our products
Quality Products
Free Shipping!
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: | 118747 |
| WARRANTY: | LIMITED 1 YEAR WARRANTY |
| WEIGHT: | 1.6 LBS |
| UNIVERSAL OR SPECIFIC FIT: | SPECIFIC |
| CIRCUIT PROTECTED: | YES |
| HARNESS TYPE: | MALE FEMALE |
| TERMINAL QUANTITY: | 4 |
| WIRE COLORS: | BROWN, GREEN, YELLOW, WHITE |
| WIRE QUANTITY: | 4 |
| WIRE GAUGE: | 16 GA. |
| 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.
Experts available to answer your questions
Call 888-634-94941 Year
6 compatible vehicles
| Year | Make & Model | Style | Notes |
|---|---|---|---|
| 2017 - 2018 | Mercedes-Benz GLC250 | Sport Utility | Tow Harness T: Connector Assembly Drilling Required Install Time is 60 minutes |
| 2016 - 2024 | Mercedes-Benz GLC300 | — | Tow Harness T: Connector Assembly Drilling Required Install Time is 60 minutes |
| 2018 - 2020 | Mercedes-Benz GLC350e | Sport Utility | Tow Harness T: Connector Assembly Drilling Required Install Time is 60 minutes |
| 2017 - 2024 | Mercedes-Benz GLC43 AMG | — | Tow Harness T: Connector Assembly Drilling Required Install Time is 60 minutes |
| 2018 - 2021 | Mercedes-Benz GLC63 AMG | Sport Utility | Tow Harness T: Connector Assembly Drilling Required Install Time is 60 minutes |
| 2018 - 2021 | Mercedes-Benz GLC63 AMG S | Sport Utility | Tow Harness T: Connector Assembly Drilling Required Install Time is 60 minutes |
Yes, the Tekonsha T-One T-Connector Harness, 4-Way Flat, w/Circuit Protected ModuLite HD Module TK118747 (Part #TK118747) is designed to fit the 2017-2018 Mercedes-Benz GLC250.
The Tekonsha T-One T-Connector Harness, 4-Way Flat, w/Circuit Protected ModuLite HD Module TK118747 (Part #TK118747) fits 2017-2018 Mercedes-Benz GLC250 models. The 2024 model year is the last year covered by this part number. For newer models, check for an updated version.
The Tekonsha T-One T-Connector Harness, 4-Way Flat, w/Circuit Protected ModuLite HD Module TK118747 (Part #TK118747) fits the following vehicles: 2017-2018 Mercedes-Benz GLC250; 2016-2024 Mercedes-Benz GLC300; 2018-2020 Mercedes-Benz GLC350e; 2017-2024 Mercedes-Benz GLC43 AMG; 2018-2021 Mercedes-Benz GLC63 AMG; 2018-2021 Mercedes-Benz GLC63 AMG S. Always verify your specific year, make, and model before ordering.
The Tekonsha T-One T-Connector Harness, 4-Way Flat, w/Circuit Protected ModuLite HD Module TK118747 (Part #TK118747) Drilling is required for installation. Basic hand tools are typically all you need.
Yes, the T-One® Connector (118747-037) is designed for the Mercedes GLC300. The installation uses the vehicle's factory taillight wiring connectors on both driver and passenger sides, with the T-connector ends inserted between the vehicle's existing connectors.
The T-One® Connector is a trailer wiring interface that taps into the vehicle's taillight wiring system. It provides a connection point for trailer lights by inserting connector ends between the vehicle's factory taillight connectors on both the driver and passenger sides, allowing you to connect a trailer without modifying the vehicle's original wiring.
Required tools are: 10 mm socket and ratchet or 10 mm wrench, drill with 3/32" drill bit, wire crimpers, wire cutters, and Phillips head screwdriver. Safety glasses must be worn during installation.
The kit includes: T-One® Connector black box, green and yellow wire harness ends, white ground wire with eyelet and screw, black 12 ga. power wire, yellow fuse holder with 15 amp fuse, yellow butt connector, double-sided tape, and cable ties. The 4-flat connector should be stored in the rear cargo area when not in use.
Yes. You must disconnect the vehicle's negative (−) battery cable before connecting the power wire to the positive (+) battery terminal. This is done in step 10, after routing the black 12 ga. power wire to the engine compartment. Reconnect the negative cable in step 12 after the fuse is installed.
You must temporarily remove the rear threshold plate and access panels on both the driver and passenger sides to reach the taillight wiring connectors. These items are reinstalled at the end of installation in step 13. The manual does not indicate that any other permanent modifications or removals are required.
Drilling may be required for the ground connection. Step 8 states you should locate an existing ground stud near the connector, but if one is not available, you must drill a 3/32" hole to secure the white ground wire using the provided eyelet and screw. Do not drill into the vehicle floor or bed. You must verify what is behind any surface before drilling to avoid damage to the vehicle or personal injury.
The T-One® Connector uses three main wires: green wire (passenger side taillight connector), yellow wire (driver side taillight connector), and white wire (ground connection). The black 12 ga. power wire is routed from the connector box to the vehicle's positive battery terminal through a 15 amp fuse holder. The yellow butt connector joins the fuse holder to the black power wire.
The black 12 ga. power wire is routed from the connector box on the passenger side along the exterior frame or following existing wiring along the thresholds into the engine compartment up to the battery. Avoid areas that may pinch or break the wire. If routing through a grommet and along the vehicle exterior, carefully avoid hot pipes, heat shields, the fuel tank, and other pinch points. The wire connects to the vehicle's positive battery terminal through a 15 amp fuse holder.
A 15 amp fuse is used. The fuse holder is provided with the kit. In step 10, after disconnecting the negative battery cable, you attach the ring terminal to the vehicle's positive battery terminal and connect the other end of the fuse holder to the black 12 ga. power wire using the yellow butt connector. The 15 amp fuse is installed in step 12 after reconnecting the negative battery cable.
Begin on the passenger side: route the harness with the green wire through the side panel opening near the threshold, up behind the tail light pocket, then insert the T-One® Connector end with the green wire between the vehicle's taillight connectors and lock into place. Then on the driver side: locate the access hole between the spare tire and rear threshold, route the connector end with the yellow wire up through the hole to the access panel, then insert it between the vehicle's taillight connectors and lock into place. Ensure locking tabs are fully engaged and not damaged.
The black box is mounted on the passenger side using the double-sided tape provided. The remainder of the harness is secured with cable ties to prevent damage or rattling, taking care to avoid areas that would cut or pinch the wire.
The white ground wire is secured using the eyelet and screw provided. Locate a suitable grounding point near the connector, such as an existing ground stud. If no existing stud is available, drill a 3/32" hole and secure the wire with the eyelet and screw. Do not drill into the vehicle floor or bed. Clean dirt and rustproofing from the area before securing.
Always wear safety glasses during installation. Before drilling, verify what is behind any surface to avoid damage to the vehicle or personal injury. Do not drill into vehicle floor, bed, or exposed surfaces. When routing the power wire, avoid hot pipes, heat shields, the fuel tank, and pinch points. Secure all wiring with cable ties to prevent damage or rattling. Read and follow all warnings and cautions printed on the tow vehicle's battery. Do not exceed the towing manufacturer rating or product amperage ratings, as overloading circuits can cause fires.
After installation is complete, test and verify the installation with a test light or trailer. For the initial test, reset the vehicle's electrical system by temporarily removing the key from the ignition. All connections must be complete for the T-One® Connector to function properly.
Store the 4-flat connector in the rear cargo area when not in use.
Do not exceed the lower of the towing manufacturer rating (including in your vehicle owner's manual) or the specific amperage ratings stated on the product. The manual specifies a 15 amp fuse, which indicates the circuit is rated for 15 amps maximum.
All connector surfaces should be clean and free of dirt before inserting the T-One® Connector ends between the vehicle's taillight connectors. This ensures proper electrical contact and secure locking.
Insert the T-One® Connector end between the vehicle's wiring connectors and lock into place by engaging the locking tabs. Be careful not to damage the locking tabs and ensure that connectors are fully inserted with locking tabs in place. This applies to both the green wire end on the passenger side and the yellow wire end on the driver side.
Yes, the T-One® Connector (118747-037) is designed for the Mercedes GLC300 and connects to the factory taillight connectors on both sides.
You need a 10 mm socket/ratchet or wrench, drill with 3/32" bit, wire crimpers, wire cutters, Phillips screwdriver, and safety glasses.
Yes, you must disconnect the negative battery cable before connecting the power wire to the positive terminal in step 10, and reconnect it after installing the 15 amp fuse in step 12.
A 15 amp fuse is used. It is installed in the yellow fuse holder provided and connects the black 12 ga. power wire to the vehicle's positive battery terminal.
Do not exceed the lower of the towing manufacturer rating in your vehicle owner's manual or the specific amperage ratings stated on the product. The 15 amp fuse indicates the circuit maximum.
On Sale Today
Original price was $93.75. Current price is $86.94.You save $6.81 (7%)
Free Shipping
Ships free on all orders
Authorized Dealer
Quick Ship
In stock and ready to ship — order now!
FREE ShippingFREE SHIPPING
Estimated delivery Wed, Sep 16 - Sat, Sep 19
Order before 2 PM EST Monday–Friday for same-day processing
Guaranteed safe & secure checkout
Matt
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
Total for 4 items:
$162.89$169.70
