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Always the correct part
We know our products
Quality Products
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Installation Point(s): S1, S2
Plugs into vehicle tail light assembly to provide a 4-way flat socket
Simple plug-and-play design eliminates the need for cutting or splicing
Plugs into vehicle tail light assembly to provide a 4-way flat socket
Battery-Powered: Yes
Converter Type: Circuit Protected, Powered, Potted
Electrical Component Location: Vehicle / Trailer
Electrical Package Type: Packaged
Electrical System Type: 2W
Material: THERMOPLASTIC RUBBER
Shipping Weight: 1.840 lbs
T-Connector Location: S1,S2
Tail Light Circuits: 6.0 Amps
Turn and Brake Circuits: 3.0 Amps
Warranty: One-Year Limited Warranty
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 Ford Transit 350 Dual Rear Wheel (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 888-634-9494One-Year Limited
2 compatible vehicles
| Year | Make & Model | Notes |
|---|---|---|
| 2015 - 2025 | Ford Transit-350 | Dual rear wheels |
| 2015 - 2025 | Ford Transit-350 HD | Dual rear wheels |
Yes, the CURT 56548 Vehicle-Side Custom 4-Pin Trailer Wiring Harness, Fits Select Ford Transit 350 Dual Rear Wheel (Part #BKDK56548) is designed to fit the 2015-2025 Ford Transit-350.
The CURT 56548 Vehicle-Side Custom 4-Pin Trailer Wiring Harness, Fits Select Ford Transit 350 Dual Rear Wheel (Part #BKDK56548) fits the following vehicles: 2015-2025 Ford Transit-350; 2015-2025 Ford Transit-350 HD. Always verify your specific year, make, and model before ordering.
The CURT 56548 Vehicle-Side Custom 4-Pin Trailer Wiring Harness, Fits Select Ford Transit 350 Dual Rear Wheel (Part #BKDK56548) fits 2015-2025 Ford Transit-350 models. The 2025 model year is the last year covered by this part number. For newer models, check for an updated version.
The CURT 56548 Vehicle-Side Custom 4-Pin Trailer Wiring Harness, Fits Select Ford Transit 350 Dual Rear Wheel (Part #BKDK56548) Refer to the included instructions for installation details. Basic hand tools are typically all you need.
The Curt 56548 is designed for SUVs and vans with 12-volt negative ground electrical systems. The wiring locations (S1–S10) shown in the manual are representative of typical SUV and van layouts, but exact fitment depends on your specific vehicle model and year. Consult your vehicle's owner's manual or contact the vehicle manufacturer to confirm your system is 12-volt negative ground before purchasing.
No. The Curt 56548 is designed only for 12-volt negative ground systems. Do not use it on 24-volt systems or positive ground systems.
The Curt 56548 has the following electrical ratings: Signal circuits (turn signals) are rated at 3.0 amps per side; Tail/Running circuits are rated at 6.0 amps total. Do not exceed the product rating or your tow vehicle's lamp load rating, whichever is lower.
You will need: ratchet, wire cutter, 6mm socket, wire crimper, 10mm socket, panel trim removal tool, T-20 Torx bit, and utility knife. Proper tools will improve the quality of installation and reduce the time required.
Yes. You must disconnect the negative battery terminal before beginning installation. This is Step 1 of the installation process. Reconnect the negative battery terminal only after all other installation steps are complete and you have reinstalled all removed items.
The installation difficulty level is rated as Difficult. Installation difficulty levels are based on time and effort involved and may vary depending on the installer's level of expertise, the condition of the vehicle, and having proper tools and equipment.
The battery is located on the driver side under the front seat. However, the manual notes that battery location may differ depending on the vehicle. Consult your vehicle's owner's manual to confirm the exact location on your specific vehicle.
Remove two T-20 Torx screws securing the taillight housing on each side (driver and passenger). After removing the screws, remove the taillight housing to access the vehicle taillight wiring harness connectors.
Open the rear cargo doors and remove the scuff panel by removing the 10mm fasteners. This provides access to route the custom wiring harness on both driver and passenger sides.
You may need to drill a hole, depending on available grounding points. Locate an existing screw or bolt in the vehicle frame to use as a grounding point. If no suitable existing fastener is available, drill a 3/32" pilot hole in an area free from rust, dirt, and paint. Clean the area with an abrasive pad or paper to remove rust and paint before securing the white ground wire with the ring terminal using the provided ground screw or an existing fastener.
You must modify the grommet that the taillight wiring harness passes through. Make a cut in the grommet from the middle outwards, ensuring it is large enough to pass the custom wiring harness housing through. After routing the custom wiring harness through the grommet, reseat the grommet using the provided sealant to seal the cut and around all wires.
The battery connection must be fuse-protected with a 10-amp maximum fuse. Exceeding this rating can cause loss of warranty, overheating, and potential fire. Install the fuse after all other installation steps are complete.
Use 12-gauge wire or larger for the power lead from the vehicle battery to the converter. Route the 12-gauge wire to the vehicle battery location, taking care to avoid pinch points and hot or rotating components.
The custom wiring harness uses the following wire colors: Yellow = Left turn; Green = Right turn; Red = Brake; Brown = Taillight. The white wire is the ground wire. The black wire is the power wire that connects to the positive battery terminal.
Route the 12-gauge black power wire from the vehicle battery as shown on the included CME-PCL-INS sheet. When passing the power wire through sheet metal, use an existing grommet, add a grommet, or use silicone to protect the power wire from sharp edges. Secure the power wire to the vehicle chassis using the provided cable ties, avoiding pinch points and hot or rotating components.
Attach the ring terminal of the white ground wire to the vehicle body using an existing screw or bolt in the vehicle frame, or using the provided ground screw. If drilling is necessary, drill a 3/32" pilot hole in an area free from rust, dirt, and paint. Clean the area with an abrasive pad or paper before securing the ground wire.
Mount the black converter box on a flat spot inside the vehicle on the driver side using the provided double-sided tape. Ensure the surface is clean and dry before adhering the converter.
Do not lay tools across the positive battery terminal (typically noted with red covers or a red '+' symbol), as this can cause a ground short leading to sparks and/or electrical shocks. Always disconnect the negative battery terminal before beginning installation. Disconnect the negative battery cable before wiring the power wire to the battery.
Before drilling any hole, check for miscellaneous items that may be hidden behind or under any surface to avoid damage and/or personal injury. This is especially important when drilling the 3/32" ground wire pilot hole.
Once the 12-volt power wire is connected to the harness, verify that the harness is functioning by attaching the battery and testing with a test light, 4-flat tester, or a functioning trailer. Ensure all connectors are fully inserted with locking tabs in place before testing.
Periodic inspection of all wires and connections should be performed to ensure there is no visible damage or loose connections. Install the provided 4-flat dust cover to prevent corrosion when the connector is not in use.
When in use, route the 4-flat to the center of the vehicle. When not in use, roll up and store in a convenient, out-of-the-way location. Secure any loose wires with the provided cable ties. Install the provided 4-flat dust cover to prevent corrosion.
Remove the taillight housing and separate the vehicle taillight wiring harness connectors from the housing, taking care not to damage the locking tabs. Insert the custom wiring harness end with the yellow wire between the separated connectors. Make sure the connectors are fully inserted with locking tabs in place. Repeat this process on the passenger side using the custom wiring harness end with the green wire.
The Curt 56548 is designed for SUVs and vans with 12-volt negative ground electrical systems. Confirm your vehicle's electrical system type in your owner's manual before purchasing.
Yes, disconnect the negative battery terminal before starting installation and reconnect it only after all other steps are complete.
Drilling may be required only if no existing screw or bolt is available for the ground wire connection. If needed, drill a 3/32" pilot hole in a rust-free, paint-free area of the vehicle frame.
The battery connection must use a 10-amp maximum fuse. Exceeding this rating can cause overheating and fire.
Use 12-gauge wire or larger for the power lead from the battery to the converter.
Periodically inspect all wires and connections for visible damage or loose connections. Install the provided 4-flat dust cover to prevent corrosion when not in use.
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