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CURT
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2019 - 2023 Lincoln Nautilus
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| Battery-Powered | Yes |
| Converter Type | Universal, Potted, Powered, Protected, PWM |
| Electrical System Type | PWM-STT |
| Finish | N/A |
| Material | Blank |
| Mount Type Description | Blank |
| Output Type | 4-Way Flat |
| Side Application Type Description | Blank |
| T-Connector Location | S1,S2 |
| Tail Light Circuits | 3.0 Amps |
| Turn and Brake Circuits | 6.0 Amps |
| Warranty | One-Year Limited Warranty |
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 |
|---|---|---|
| 2019 - 2023 | Lincoln Nautilus | — |
The kit includes: one 30 amp auto-resetting circuit breaker, two #10 ring terminals, two 3/8" ring terminals, two 1/2" ring terminals, three 12-10 gauge butt connectors, 10 feet of 10 ga black/white duplex wire, 20 feet of 10 ga blue cross-linked wire, and eight 8.5" cable ties.
Yes, but with a critical difference: these vehicles require the stop signal wire to be spliced to the light green wire on the turn signal harness connector under the dash, not to the brake pedal switch. Do NOT connect to the red wire with green stripe, as serious damage may occur. All other vehicles connect to the brake pedal switch instead.
You will need: a test light, wire stripper/cutter, crimp tool, and 3/8" box end wrench. The test light is used to identify the cold (switched) side of the brake pedal switch.
Yes. The manual cautions to disconnect the tow vehicle's negative battery cable before installation. Reconnect it only in the final step after all wiring is complete.
Mount the 30 amp circuit breaker near the tow vehicle's positive battery terminal. This keeps the power wire run as short as possible and protects the circuit.
Use 10 gauge (10 ga) black wire from the duplex wire included in the kit. Strip 3/8" of insulation from each end. Crimp a #10 ring terminal to the end that attaches to the circuit breaker stud labeled 'BAT', and a 3/8" or 1/2" ring terminal (sized to fit your battery terminal) to the end that attaches to the positive battery terminal.
Feed the 10 ga duplex wire from the brake controller in the cockpit through the firewall into the engine compartment toward the battery. Cut to length as needed. At the battery end, crimp a 3/8" or 1/2" ring terminal to the white wire and a #10 ring terminal to the black wire. Attach the black wire to the circuit breaker stud labeled 'AUX' and tighten the nut with a 3/8" box end wrench.
When passing the duplex wire through the firewall into the engine compartment, use an existing grommet, add a new grommet, or fill the hole with silicone rubber to insulate and protect the wire. The same protection applies when passing the blue cross-linked wire through any sheet metal at the rear of the vehicle.
In the cockpit, attach the black duplex wire to the brake controller's battery wire (typically black) and the white duplex wire to the brake controller's ground wire (typically white). Use either one of the supplied yellow butt connectors or solder the leads together and insulate with heat shrink tubing.
Locate the brake pedal switch on the back side of the vehicle's brake pedal. Use a test light or volt meter to identify the 'cold' or switched side—this terminal will only show power when the brake pedal is depressed. Attach the stop signal wire (typically red) from the brake controller to the cold side of the switch using a wire tap.
Locate the semi-circle turn signal harness connector on the steering column under the dash. It has two rows of wires: a row of four and a row of seven. Attach the stop signal wire (typically red) from the brake controller to the light green wire using a wire tap. Do NOT connect to the red wire with green stripe, as serious damage may occur.
Feed the 10 ga blue cross-linked wire from the brake controller to the trailer connector at the rear of the vehicle, taking up any slack in the wire. When passing through any sheet metal, use an existing grommet, add a new grommet, or fill the hole with silicone rubber to protect the wire.
Attach the blue cross-linked wire to the brake controller's electric brake wire (typically blue) using one of the supplied yellow butt connectors or by soldering and insulating with heat shrink tubing. At the rear of the vehicle, trim any loose blue wire and attach it to the trailer connector's electric brake terminal. Refer to the trailer connector's wiring diagram for the correct terminal location.
Secure any loose wires with the cable ties provided. Connect the black power wire from the circuit breaker to the positive side of the battery. Connect the white ground wire from the brake controller to the negative side of the battery. Finally, reconnect the tow vehicle's negative battery cable to the battery.
The circuit breaker is 30 amps and auto-resetting. It must be mounted near the positive battery terminal and connected directly to the positive battery terminal via the included black 10 gauge wire.
Use a 3/8" box end wrench to tighten the nuts on the circuit breaker studs labeled 'BAT' and 'AUX'.
The kit includes 10 feet of 10 gauge black/white duplex wire for the battery and brake controller connections, and 20 feet of 10 gauge blue cross-linked wire for the electric brake signal to the trailer connector.
Black wire connects to the positive battery and circuit breaker. White wire connects to the brake controller ground and negative battery. Red wire is the stop signal wire from the brake controller. Blue wire is the electric brake signal wire. The manual notes these are 'typically' these colours but recommends confirming with your brake controller documentation.
Yes. You can solder the leads together and insulate with heat shrink tubing as an alternative to using the supplied yellow butt connectors. This applies to connections between the duplex wire and the brake controller wires, and between the blue cross-linked wire and the brake controller.
The black power wire must connect directly to the positive battery terminal via the 30 amp circuit breaker. Connecting to the fuse panel or any other accessory wiring may damage vehicle wiring and cause trailer brake failure. The circuit breaker protects the circuit and must be the only protection between the battery and the brake control system.
Do NOT connect the stop signal wire to the red wire with green stripe on the turn signal harness. Serious damage may occur. Connect only to the light green wire. Also, do not connect to the brake pedal switch on these vehicles; use the turn signal harness instead.
The kit is universal but requires an existing trailer connector and brake controller. 1989-1991 Ford E & F-Series with ABS use a different stop signal connection (turn signal harness instead of brake pedal switch). Consult your brake controller documentation for compatibility.
No drilling is required. The kit connects to existing components: the battery, brake controller, brake pedal switch (or turn signal harness on 1989-1991 Ford E & F-Series with ABS), and trailer connector.
Do NOT connect the stop signal wire to the red wire with green stripe on the turn signal harness—serious damage may occur. Connect to the light green wire instead, and do not use the brake pedal switch.
Connecting to the fuse panel or accessory wiring may damage vehicle wiring and cause trailer brake failure. The 30 amp circuit breaker must be the only protection between the battery and the brake control system.
The Curt 56446 is a custom wiring harness with a powered converter system designed for SUVs and vans. It provides signal circuits (6.0 amps per side) and tail/running circuits (3.0 amps total) to connect your vehicle's lighting system to a trailer. The system includes a converter box that converts the vehicle's factory taillight signals for use with a 4-flat trailer connector.
The Curt 56446 is designed for SUVs and vans. The system is compatible only with 12 volt negative ground systems. For specific vehicle model and year compatibility, contact Curt Manufacturing or consult your vehicle's owner's manual to confirm your vehicle has a 12 volt negative ground electrical system.
Required tools are: ratchet, T-20 Torx bit, socket extension, cutting tool, fishwire (or stiff wire, rope or string), wire crimper, electrical tape, wire stripper, and flathead screwdriver. Proper tools will improve installation quality and reduce installation time.
The manual shows a hardware photo but does not itemize individual components. The product includes: a converter box, a 4-flat connector, double-sided tape for mounting the converter, a white ground wire with ring terminal, a black power wire, cable ties, a 4-flat dust cover, and a screw for ground wire installation. Refer to the product packaging or contact Curt Manufacturing for a complete parts list.
Yes. Step 1 requires you to locate the vehicle's battery in the engine compartment on the driver side and disconnect the negative battery terminal. Fasten this wire down and away from the battery while completing the installation. The battery must remain disconnected until Step 7, when you reconnect it after all other wiring is complete and before testing.
Open the rear hatch. Using a small screwdriver, remove the fastener cover. Using a T-20 Torx bit, remove the fastener holding the taillight. Remove the taillight by pulling it straight rearward and then outward to the side of the vehicle. Locate the vehicle taillight wiring connectors and separate them from the taillight housing, taking care not to damage the locking tabs. Repeat on the other side of the vehicle.
Fishwiring is a method to push or pull an electrical wire through a blind hole. Insert a stiff wire, rope, string, or cut-up wire hanger (the 'fishwire') through the blind hole and locate it on the other side. Use tape to secure the harness to the fishwire and pull back up. If the fishwire gets hung up, you may need to push back down, wiggle it around, or twist the wire to loosen it. Make sure the fishwire is long enough to stick out on the other side before starting.
On the driver side, route the fishwire down between the body and the bumper cover. From under the vehicle, locate and attach the fishwire to the housing with the yellow wire. Pull the wire back up and attach to the factory harness. Make sure the connectors are fully inserted with locking tabs in place.
Route the green wire along the backside of the bumper cover. Use cable ties to secure any loose wire as needed.
On the passenger side, route the fishwire down between the body and the bumper cover. From under the vehicle, locate and attach the fishwire to the housing with the yellow wire. Pull the wire back up and attach to the factory harness. Make sure the connectors are fully inserted with locking tabs in place.
Locate a flat spot inside the vehicle near the yellow wire and adhere the black converter box using the provided double-sided tape. The area should be clean and suitable for tape adhesion.
Not necessarily. Locate a suitable grounding point near the converter box connector, such as an existing screw with nut in the vehicle frame. If no suitable existing screw is available, drill a 3/32" pilot hole for the provided screw. The area should be free of rust, dirt and paint. Before drilling, check for miscellaneous items that may be hidden behind or under any surface to avoid damage and personal injury.
Drill a 3/32" pilot hole for the provided ground wire screw. The area should be free of rust, dirt and paint. Before drilling, check for miscellaneous items that may be hidden behind or under any surface to avoid damage and personal injury.
Secure the white ground wire using the ring terminal and the provided screw. Attach the ring terminal to a suitable grounding point near the converter box connector, such as an existing screw with nut in the vehicle frame, or drill a 3/32" pilot hole if necessary. The area should be free of rust, dirt and paint.
Use 12 GA (12 gauge) wire or larger to route from the vehicle battery to the converter system. Route the 12 GA wire to the vehicle battery location, taking care to avoid any pinch points and hot or rotating components.
The black power wire connects to the positive (+) battery terminal. Route the black power wire from the vehicle battery as shown on the provided Powered Converter Lead Instruction Sheet. Use a ring terminal for the battery connection.
The wire colors and their functions are: Green = Right turn, Red = Brake, Yellow = Left turn, Brown = Taillight. These wires connect the factory taillight signals to the converter system for trailer lighting control.
The signal circuits are rated for 6.0 amps per side. Do not exceed this rating or the tow vehicle lamp load rating, whichever is lower. Exceeding the product rating can cause loss of warranty, overheating and potential fire.
The tail and running circuits are rated for 3.0 amps total. Do not exceed this rating or the tow vehicle lamp load rating, whichever is lower. Exceeding the product rating can cause loss of warranty, overheating and potential fire.
The battery connection must be fuse-protected with a 15-amp maximum fuse. Install the fuse after all other steps are complete. Exceeding the product rating can cause loss of warranty, overheating and potential fire.
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. This prevents damage to the wire insulation and potential electrical hazards.
Use the provided cable ties to secure any loose wire as needed. Secure the power wire to the vehicle chassis using cable ties provided. This prevents wires from moving, rubbing, or becoming pinched during vehicle operation.
Route the 4-flat to the trailer hitch and mount in an easy-to-access location. Install the provided 4-flat dust cover to help prevent corrosion.
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. This confirms all connections are correct and the system is operating properly before final reassembly.
Periodic inspection of all wires and connections should be performed to ensure there is no visible damage or loose connections. This helps maintain proper function and prevents electrical failures.
No. The converter system is to be used only on 12 volt negative ground systems. It is not compatible with 24 volt systems or positive ground systems.
Before drilling, check for miscellaneous items that may be hidden behind or under any surface to avoid damage and personal injury. This includes checking for fuel lines, brake lines, electrical wiring, and other components that could be damaged by drilling.
After disconnecting the negative battery terminal, fasten this wire down and away from the battery while completing the installation process. This prevents accidental reconnection and electrical hazards during installation.
After completing all wiring steps and testing the system with a test light, 4-flat tester, or functioning trailer, reinstall all items removed during installation. If the negative battery terminal was disconnected at the beginning, reconnect it. Install the provided 4-flat dust cover to help prevent corrosion.
The Curt 56446 is designed for SUVs and vans with 12 volt negative ground electrical systems. Confirm your vehicle meets these requirements before purchasing.
Yes, you must disconnect the negative battery terminal before beginning installation and keep it disconnected until after all wiring is complete and tested.
Drilling is only required if no suitable existing screw is available for the ground wire. If needed, drill a 3/32" pilot hole. Always check for hidden items before drilling.
Use a 15-amp maximum fuse for the battery connection. Install the fuse after all other steps are complete.
Use 12 GA (12 gauge) wire or larger for the power wire from the battery to the converter system.
Periodically inspect all wires and connections to ensure there is no visible damage or loose connections.
If the fishwire gets hung up on something during routing, you may have to push back down, wiggle it around, or twist the wire to loosen it from what it's hung up on. Ensure the fishwire is long enough to stick out on the other side before starting, and use tape to secure the harness to the fishwire before pulling.
When removing the taillight connectors, take care not to damage the locking tabs. If connectors are difficult to separate, gently wiggle them while pulling to avoid breaking the tabs. Ensure the connectors are fully inserted with locking tabs in place when reconnecting to the factory harness.
The 4-way flat electrical adapter converts a vehicle's 4-way flat trailer connector to other trailer connector types (6-way round, 7-way RV blade, or dual 4-way flat). This allows you to tow trailers with different connector styles. Single-output models (57184, 57183, 57185, 57626, 57676) convert to one connector type; dual-output models (57604, 57624, 57672, 57674, 57102) provide two different connector outputs simultaneously.
Yes. Your vehicle must be equipped with a 4-way flat trailer connector. If your vehicle does not have one, you will need to install a custom wiring harness or other 4-way flat trailer connector before installing this adapter.
Both convert a 4-way flat connector to a 7-way RV blade. The difference is that 57185 includes a mounting bracket, while 57184 does not.
Both convert a 4-way flat connector to a 6-way round. The difference is that 57626 includes a mounting bracket, while 57183 does not.
Curt offers three dual-output models that provide both a 4-way flat and a 7-way RV blade output: part numbers 57672, 57674, and 57102. All three include a mounting bracket.
Curt offers two dual-output models that provide both a 4-way flat and a 6-way round output: part numbers 57604 and 57624. Both include a mounting bracket.
You will need: a 1/8" drill bit, drill, Phillips screwdriver, wire stripper, cutting tool, terminal crimpers, and a test light. The manual also lists three self-tapping screws (#10 - 1/2") as required, though these are not included with the product.
No. The three self-tapping screws (#10 - 1/2") used to attach the mounting bracket are not included and must be purchased separately.
Mount the combination harness in a location on the tow vehicle that is within reach of the trailer's wiring harness and near the center of the vehicle. The mounting bracket (if included) should be attached to the vehicle's bumper or other suitable surface.
Yes. You must drill two 1/8" holes: one for the grounding point and one (or more) for the mounting bracket. Before drilling, you must check for brake lines, fuel lines, wiring and other components that may be hidden behind or under the surface to avoid damage.
No. You must never attach the mounting bracket directly to the hitch by cutting, welding or drilling into the hitch. Mount it to the vehicle's bumper or other suitable surface instead.
The adapter uses four wires: Yellow (auxiliary or back-up lights), Blue (electric brakes), Black (positive power with appropriate inline fuse), and White (ground). All wires except black and white must be connected using 12 gauge (minimum) wire and butt connectors to the appropriate vehicle functions.
The white wire is the ground connection. It must be attached with a ring terminal to a 1/8" hole drilled in a suitable grounding point on the vehicle using a #10 - 1/2" self-tapping screw. This ground connection is required for the harness to work properly. The white wire on the vehicle's 4-way flat connector does not support the ground (-) functions of the combination harness.
Yes. The black wire (positive power) must be connected with an appropriate inline fuse. The manual does not specify the fuse amperage rating.
Use 12 gauge (minimum) wire for all connections. The manual specifies this minimum gauge for the remaining wires (yellow, blue, and black) when connecting to appropriate vehicle functions.
Failing to properly ground the product can cause loss of warranty, overheating and potential fire. The white wire must be securely attached to a clean grounding point using a #10 - 1/2" self-tapping screw in a 1/8" hole. The area must be clean of dirt, debris or undercoating.
Do not exceed the product rating or the tow vehicle lamp load rating, whichever is lower. Exceeding either rating can cause damage or unsafe operation.
Confirm proper function with a test light or by using a properly functioning trailer. This verifies that all connections are working correctly before towing.
Secure any loose wires using cable ties or equivalent product to prevent them from moving, catching on components, or becoming damaged.
Your vehicle must have a 4-way flat trailer connector. If it does not, you will need to install a custom wiring harness or other 4-way flat connector first. Check the part number table to confirm the adapter converts to the connector type you need.
You must purchase three #10 - 1/2" self-tapping screws for the mounting bracket. You will also need an appropriate inline fuse for the black (positive power) wire; the manual does not specify the amperage.
Yes, you must drill two 1/8" holes: one for grounding and one for the mounting bracket. Before drilling, check for brake lines, fuel lines and wiring behind the surface. Never drill into the hitch.
Yellow = auxiliary/back-up lights; Blue = electric brakes; Black = positive power (needs inline fuse); White = ground (must be properly grounded or warranty is void and fire risk exists). Use 12 gauge minimum wire and butt connectors.
Proper grounding of the white wire is critical. Failing to ground it properly can cause loss of warranty, overheating and fire. The grounding point must be clean of dirt, debris and undercoating.
Test with a test light or by using a properly functioning trailer to confirm all connections work. Secure loose wires with cable ties.
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