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| Battery-Powered | Yes |
| Converter Type | Universal, Potted, Powered, Protected, PWM |
| Electrical System Type | 3W |
| Finish | Blank |
| Material | Blank |
| Mount Type Description | Not Applicable |
| Output Type | 4-Way Flat |
| Side Application Type Description | Not Applicable |
| T-Connector Location | S3,S4 |
| Tail Light Circuits | 7.5 Amps |
| Turn and Brake Circuits | 7.5 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 |
|---|---|---|
| 2014 - 2024 | Ram ProMaster 3500 | Excluding remote proximity keyless entry |
Yes, the 14 - 24 RAM ProMaster 3500 Excluding remote proximity keyless entry CURT Trailer Brake Controller 7-Way Upgrade Kit 7WK2161 (Part #7WK2161) is designed to fit the 2014-2024 Ram ProMaster 3500.
The 14 - 24 RAM ProMaster 3500 Excluding remote proximity keyless entry CURT Trailer Brake Controller 7-Way Upgrade Kit 7WK2161 (Part #7WK2161) fits 2014-2024 Ram ProMaster 3500 models. The 2024 model year is the last year covered by this part number. For newer models, check for an updated version.
The 14 - 24 RAM ProMaster 3500 Excluding remote proximity keyless entry CURT Trailer Brake Controller 7-Way Upgrade Kit 7WK2161 (Part #7WK2161) fits the following vehicles: 2014-2024 Ram ProMaster 3500. Always verify your specific year, make, and model before ordering.
The 14 - 24 RAM ProMaster 3500 Excluding remote proximity keyless entry CURT Trailer Brake Controller 7-Way Upgrade Kit 7WK2161 (Part #7WK2161) Refer to the included instructions for installation details. Basic hand tools are typically all you need.
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.
Part 56478 is designed for SUVs and Vans. The manual does not list specific vehicle makes, models or years. Contact Curt Manufacturing or consult a fitment database to confirm compatibility with your vehicle before purchasing.
The 56478 is a wiring converter for SUVs and Vans that integrates with the vehicle's taillight wiring system. It includes a converter box, custom wiring harness with color-coded wires (yellow for left turn, green for right turn, red for brake, brown for taillight), a power lead that connects to the vehicle battery, and a 4-flat connector for external use. The manual does not specify whether it is for trailer lighting, towing, or another application.
Yes. The converter system is designed only for 12-volt negative ground electrical systems. Do not use on any other system type.
Required tools are: ratchet, 10 mm socket, Phillips screwdriver, flathead screwdriver, panel trim removal tool, wire stripper, wire crimper, electrical tape, and cutting tool. Proper tools will improve installation quality and reduce time required.
Yes. You must disconnect the negative battery terminal before beginning installation. The battery is located under the driver-side floor panel, secured by six fasteners. Remove the floor panel to access it. Reconnect the negative battery terminal after all other installation steps are complete and before installing the fuse.
Mount the black converter box on the upper corner inside the rear cargo door frame on the driver side using the provided double-sided tape. The area should be flat and clean. Ensure the area is free of rust, dirt and paint before adhering.
Open the rear cargo doors. On the driver side, remove seven Phillips screws from the plastic cover to locate the vehicle taillight wiring harness connectors. Separate the connectors from the taillight housing, taking care not to damage the locking tabs. Insert the custom wiring harness end with the yellow wire between the separated connectors, ensuring they 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.
Route the custom wiring harness end with the green wire to the passenger side through the opening that runs up and over the rear cargo doors. This connects the passenger-side taillight connector to the converter system.
Drilling may be required for the ground wire connection. Locate a suitable grounding point near the connector, such as an existing screw with nut in the vehicle frame. If no suitable point exists, 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 behind or under the surface to avoid personal injury or property damage.
Locate a suitable grounding point near the connector, such as an existing screw with nut in the vehicle frame, or drill a 3/32" pilot hole for the provided screw. The area must be free of rust, dirt and paint. Remove the nut from the existing screw or the provided screw, install the white ground wire ring terminal, and replace the nut to secure it.
Route the black power wire from the vehicle battery as follows: start at the wiring harness converter box, along the top of the driver-side cargo area and down along the frame located behind the driver seat. Continue from the cargo area along the bottom of the driver-side seat frame and route the power wire under the floor panel section to the battery. Use the provided cable ties to secure any loose wires. When passing the power wire through sheet metal, use an existing grommet, add a grommet, or use silicone to protect the wire from sharp edges. Avoid pinch points and hot or rotating components.
Remove the Phillips screws from the plastic seat belt trim panel and the trim around the driver-side seat and floor. Remove all plastic trim panels to allow routing of the power wire from the converter box to the battery. These panels are reinstalled after the power wire is routed.
Use a 10-amp fuse maximum. The battery connection must be fuse-protected with a 10-amp max fuse. Install the fuse after all other installation steps are complete. Do not exceed this rating, as exceeding the product rating can cause loss of warranty, overheating and potential fire.
Signal circuits are rated at 7.5 amps per side. Tail/running circuits are rated at 7.5 amps total. Do not exceed the product rating or the tow vehicle lamp load rating, whichever is lower.
Yellow = Left turn; Green = Right turn; Red = Brake; Brown = Taillight. The converter also includes a white ground wire and a black power wire that connects to the vehicle battery positive terminal.
Use 12-gauge wire or larger for the power connection from the converter to the vehicle battery. The manual specifies '12 GA wire or larger' for the power lead.
When in use, route the 4-flat connector to the center of the vehicle and out of the cargo area. When not in use, roll it up and store in a convenient, out-of-the-way location inside the trunk. Install the provided 4-flat dust cover to help prevent corrosion.
Disconnect the negative battery terminal before beginning installation. 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, resulting in sparks and/or electrical shocks. Use a ring terminal for the battery connection. Disconnect the negative battery cable before wiring the power wire to the battery.
Before drilling, check for miscellaneous items that may be behind or under the surface to avoid personal injury or property damage. This is especially important when drilling the 3/32" pilot hole for the ground wire connection.
Once installed, test for proper function by using a test light or connecting a properly wired trailer. All installation steps must be followed to ensure the product functions properly.
Perform periodic inspection of all wires and connections to ensure there is no visible damage or loose connections. No other maintenance intervals are specified in the manual.
The installation difficulty is rated as Easy. Installation difficulty levels are based on time and effort involved and may vary depending on the installer's level of expertise, condition of the vehicle, and proper tools and equipment.
Open the rear cargo doors. On each side (driver and passenger), remove seven Phillips screws from the plastic cover to locate the vehicle taillight wiring harness connectors. These covers provide access to the connectors you need to separate and integrate with the custom wiring harness.
The 56478 is designed for SUVs and Vans. Consult a fitment database or contact Curt Manufacturing to confirm compatibility with your specific vehicle make, model and year.
Yes, disconnect the negative battery terminal before starting. The battery is under the driver-side floor panel, secured by six fasteners. Reconnect it after all other steps are complete, before installing the fuse.
Drilling may be required. If no existing screw with nut is available for the ground wire connection, drill a 3/32" pilot hole. Before drilling, check for items behind or under the surface to avoid injury or damage.
Use a 10-amp fuse maximum. Install it after all other steps are complete. Do not exceed this rating to avoid loss of warranty, overheating and potential fire.
Use 12-gauge wire or larger for the power lead from the converter to the battery. Route it avoiding pinch points and hot or rotating components.
The converter is designed only for 12-volt negative ground electrical systems. Do not use on any other system type.
Perform periodic inspection of all wires and connections to ensure there is no visible damage or loose connections.
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.
Before drilling, you must check for brake lines, fuel lines, wiring and any other components that may be hidden behind or under the surface. Drilling into these components can cause damage and personal injury.
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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