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Warranty: One-Year Limited Warranty
Electrical System Type: 2W
Output Type: 4-Way Flat
Tail Light Circuits: 6.0 Amps
Turn and Brake Circuits: 3.0 Amps
Installation Difficulty: Professional
Installation Time Exact (Minutes): 45
If your vehicle is not equipped with wiring for towing a trailer, CURT custom wiring is the ideal solution. A custom wiring harness -- also called a T-connector -- is a simple, plug-and-play electrical device that plugs into your automotive electric system and provides a standard, universal trailer wiring connection. This is done using two or more vehicle-specific, OEM-compatible connectors to plug into the taillight assembly, eliminating the need for cutting, splicing and soldering during installation. Custom wiring harnesses are made vehicle-specific, and while they are not available for all vehicles, they do offer one of the fastest, easiest and most secure ways to wire a vehicle for towing. This particular plug-in harness provides a 4-way flat connector socket and is designed to be a custom wiring harness to fit certain years of the Lincoln MKX (to verify your vehicle compatibility, see application info). It comes with all necessary wiring components to establish a reliable trailer wiring connection, as well as a dust cover to keep the connector clean when not in use. You have a picture in mind of your next destination -- maybe it's the boat landing at your favorite fishing spot, maybe it's a campsite that overlooks one of nature's masterpieces, or maybe it's the next big jobsite. However, turning that picture into a reality takes more than just daydreaming. It takes a solid connection and the right amount of power. CURT custom wiring is made with some of the most sophisticated technology in the industry and is designed to install with ease, giving you a long-lasting electrical connection for your towing hitch setup.
CURT offers a variety of high-quality trailer hitches and accessories for select vehicle models. Find the perfect fit for your towing needs at TowUniverse.
CURT, a Lippert brand, offers a complete line of towing products and is the leading manufacturer of custom-fit trailer hitches. We offer the broadest selection of custom-fit hitches, and each one is designed, welded, and coated in Wisconsin.
CURT is also a leader in flat towing products, as well as 5th wheel, gooseneck, and weight distribution hitches, ball mounts, electrical components, cargo solutions, and other towing accessories.
For everything from passenger cars and vans to full-size pickups and SUVs, CURT is 'The First Name in Towing Products®.'
Experts available to answer your questions
Call 888-634-94941 compatible vehicles
| Year | Make & Model | Notes |
|---|---|---|
| 2011 - 2015 | Lincoln MKX | Installation Time: 30-60 minutes |
The CURT 56121 Vehicle-Side Custom 4-Pin Trailer Wiring Harness, Fits Select Lincoln MKX (Part #BKDK56121) fits 2011-2015 Lincoln MKX models. The 2015 model year is the last year covered by this part number. For newer models, check for an updated version.
Yes, the CURT 56121 Vehicle-Side Custom 4-Pin Trailer Wiring Harness, Fits Select Lincoln MKX (Part #BKDK56121) is designed to fit the 2011-2015 Lincoln MKX.
The CURT 56121 Vehicle-Side Custom 4-Pin Trailer Wiring Harness, Fits Select Lincoln MKX (Part #BKDK56121) fits the following vehicles: 2011-2015 Lincoln MKX. Always verify your specific year, make, and model before ordering.
The CURT 56121 Vehicle-Side Custom 4-Pin Trailer Wiring Harness, Fits Select Lincoln MKX (Part #BKDK56121) Typical installation time is 30-60 minutes. Basic hand tools are typically all you need.
Yes, the Curt 56121 is designed for the Lincoln MKX. It is a custom wiring harness for SUVs, mini and full-sized vans.
The Curt 56121 is a custom wiring harness that integrates with your vehicle's taillight system. It includes a converter box and a 4-flat connector for trailer use. The harness handles signal circuits (3.0 amps per side) and tail/running circuits (6.0 amps total).
You will need a ratchet, 10mm socket, and panel trim removal tool. You may also need a drill if you do not have a suitable existing screw for the ground wire attachment.
The harness includes a custom wiring harness with yellow and green wire ends, a black converter box, a white ground wire with ring terminal, a provided screw for grounding, double-sided tape for the converter box, cable ties, sealant for the grommet, and a 4-flat dust cover.
Yes. You must open the vehicle tailgate and remove the two 10mm bolts securing the taillight, then carefully pull the taillight rearward without damaging the locking tabs. This gives you access to the taillight wiring harness connectors.
You must remove the floor mats, spare tire compartment cover, rear scuff panel, and plastic storage trays surrounding the spare tire. These removals provide access to route the wiring harness from the taillight area through the interior.
Drilling may be required. You must locate a suitable grounding point near the connector, such as an existing screw with nut in the vehicle frame. If no existing screw is available, you will need to drill a 3/32" pilot hole for the provided screw. The area must be free of rust, dirt and paint before installation.
Yes. You must locate the grommet behind the taillight where the vehicle taillight wiring passes through from inside the cabin. Remove the grommet and cut a slit large enough to route the custom wiring harness through it. After routing the harness, reseat the grommet using the provided sealant to seal the cut and around all wires.
The harness has three main wires: yellow wire (driver side taillight connection), green wire (passenger side taillight connection), and white ground wire (vehicle frame grounding point). The black converter box connects to the vehicle battery via a black power wire, which must be routed as shown on the included CME-PCL-INS sheet.
Yes. The battery connection must be fuse-protected with a maximum 10-amp fuse. Exceeding this rating can cause loss of warranty, overheating and potential fire. Do not exceed the product rating or tow vehicle lamp load rating, whichever is lower.
Separate the vehicle's taillight wiring harness connectors from the taillight housing, taking care not to damage the locking tabs. Route the custom harness end with the yellow wire (driver side) or green wire (passenger side) through the grommet slit. Insert the custom harness end between the separated connectors and ensure the connectors are fully inserted with locking tabs in place.
Locate a flat spot inside the vehicle near the taillight and adhere the black converter box using the provided double-sided tape.
When not in use, roll up the 4-flat connector and store it in a convenient, out-of-the-way location inside the trunk. When in use, route it to the center of the vehicle and out of the trunk. Secure any loose wires with the provided cable ties.
All steps must be followed to ensure the wiring harness functions properly. Test for proper function by using a test light or connecting a properly wired trailer. This confirms that the signal and tail/running circuits are operating correctly.
Before drilling, check for miscellaneous items that may be hidden behind or under any surface to avoid damage and personal injury. The area for the ground wire screw should be free of rust, dirt and paint.
The product is rated for signal circuits of 3.0 amps per side and tail/running circuits of 6.0 amps total. The battery connection must be fuse-protected with a 10-amp maximum fuse. Do not exceed the product rating or tow vehicle lamp load rating, whichever is lower, as this can cause loss of warranty, overheating and potential fire.
Yes, the Curt 56121 is designed for the Lincoln MKX and other SUVs, mini and full-sized vans.
You need a ratchet, 10mm socket, and panel trim removal tool. A drill may be needed if you do not have an existing screw for the ground wire.
Drilling may be required if no existing screw is available for the ground wire. You would drill a 3/32" pilot hole in the vehicle frame.
Yes, the battery connection must be fuse-protected with a maximum 10-amp fuse. Exceeding this can cause overheating and fire.
Signal circuits are rated 3.0 amps per side; tail/running circuits are 6.0 amps total. Do not exceed the product rating or vehicle lamp load rating, whichever is lower.
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