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Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector

Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector

Item # C56190
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Install a 4-way flat on your vehicle with this splice-in harness. Requires 55151 (sold separately) to connect module to car battery for power. SMT construction ensures superior performance. Works with 2-wire and 3-wire systems. Lowest Prices for the best trailer wiring from CURT. Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector part number C56190 can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (23)
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CURT Trailer Wiring - C56190

  • Trailer Connectors
  • Vehicle End Connector
  • 4 Flat
  • Plug and Lead
  • CURT

Install a 4-way flat on your vehicle with this splice-in harness. Requires 55151 (sold separately) to connect module to car battery for power. SMT construction ensures superior performance. Works with 2-wire and 3-wire systems.


  • Provides a 4-way flat trailer connector at the back of your vehicle to power your trailer's signal lights
    • Compatible with 5-pole, 6-pole and 7-pole adapters (sold separately)
  • Ensures that your vehicle's wiring matches that of your trailer
    • Works with 2-wire and 3-wire electrical systems
  • Requires 55151 (sold separately) to connect module to car battery for power
  • Constructed using surface-mount technology (SMT) for consistent, reliable performance
    • Maximizes trailer light yield and intensity while producing minimal heat
    • Ensures superior operation in rough road conditions
  • Resists water and vibration
  • Connects directly to your vehicle's wiring with the included quick-splice connectors
    • Color-coded wires and wiring guide ease installation
  • Comes with dust cap for 4-way flat connector


  • Maximum amperage:
    • Stop/turn lights: 4.2 amps per circuit
    • Tail lights: 7.5 amps per circuit
  • Limited 1-year warranty


To determine where to splice into your vehicle's tail light wiring, you will need to consult the included instructions. Use the quick-splice connectors to attach the input wires of the tail light converter to the corresponding wires from your vehicle. To get the power necessary to operate, the harness must be connected to a 12V power source. To do this, you will need the Curt powered converter wiring kit (55151 - sold separately), which contains the power wire that connects your battery.

Then locate a flat surface inside your vehicle near the tail lights and adhere the black converter box using the provided double-sided tape. Find a raw metal surface to use as a ground point and secure the white ground wire using the provided ring terminal and screw. Finally, secure the converter wires to your vehicle using the included cable ties.

It is recommended that you use a small amount of dielectric grease on the 4-pole connector to help prevent corrosion.

Powered Tail Light Converter with Surface-Mount Technology

Because most trailers run on a 2-wire system - wherein the brake and turn signals are carried on 1 wire - the signals from your vehicle may have to be converted to be compatible with your trailer's wiring. If your vehicle operates on a 3-wire system, which means that it has separate brake and turn signals, then those signals will need to be combined so that they run on 1 wire to properly activate your trailer's tail lights. Note: This will not affect how the tail lights on your vehicle operate.

This converter is a circuit-protected, battery-powered unit that bypasses the electrical routes that are used by a basic wiring harness. As a result, there is virtually no draw on your tail light circuits.

Curt builds each tail light converter using surface-mount technology (SMT). This method of construction involves soldering electronic components directly to the surface of a printed circuit board. SMT eliminates the need for leads, which are used in older through-hole technology. The result is a circuit board that is smaller yet provides more routing area and that offers superior performance, reliability and durability.

Curt SMT Circuit Boards

Circuit boards constructed using SMT have been shown to perform better under rough conditions with excessive vibration than those made using the through-hole method. And where would vibration be more likely to occur than in towing applications? Curt converters also produce less heat, leading to increased durability and longer life. In addition, lower levels of resistance ensure better performance, especially for parts that operate at higher frequencies.

Each Curt circuit board is made using high-quality components that are pieced together in the most technologically savvy fashion, leading to greater predictability and reliability in functioning.

56190 Curt Powered Tail Light Converter for 2-Wire, 3-Wire or PWM Systems - 4-Way Flat Harness

Installation Details C56190 Installation instructions

California residents: click here

Customer Reviews

Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector - C56190

Average Customer Rating:  4.7 out of 5 stars   (23 Customer Reviews)

Install a 4-way flat on your vehicle with this splice-in harness. Requires 55151 (sold separately) to connect module to car battery for power. SMT construction ensures superior performance. Works with 2-wire and 3-wire systems.


I didnt do the installation.. My friend /mechanic that did the rewiring said it was quality & easy to work with


After figuring out the Sprinter wiring the installation was easy. Works great.

No problems. Good deal!
Greg K - 08/03/2021


Everything was quite straight-forward and worked as expected. The only downside was the length of the green wire. My routing on a BMW X3 (not a huge vehicle) was straight across the rear of the vehicle to the passenger side wiring. But the green wire was so short, I had to move the mounting location of the module to avoid adding a splice. Another foot of green wire would be a plus.


I received the product pretty quickly the box was torn from the weight of the metal and some parts were not secured. The wiring kit didn't have enough black wire to run to the battery and there was no fuse or fuse holder to attach to that line connected to the took around 3 hours to install completly.


Product arrived more quickly than promised and the hitch was easy to install. I have not yet installed the wiring kit, but it looks very straightforward. Thanks.


Not that easy to install. I ended up finding another harness that doesn't require tapping into the existing wiring like this one. I wish I would've found it first.


This trailer wire and plug was simple to install and I have had no issues with it, I definitely would recommend this to anyone else.


I have used etrailer a couple of times now, and I have always been very happy with the products & service.




Very fast delivery and excellent pricing. I will use again and again


The converter shipped promptly. I got it installed and it works perfect. I would recommend retailer to everyone.


Easy to install and works great.


Super speedy delivery! Thank you!
worked like a charm too!


Great product, hard install on 2014 mdx. Looks real good after install.


Looks very goos.


It's exactly what I was looking for and exactly as described on the website. Everything was properly labeled and easy to install


Quality products, good prices, delivered on time


great service. came really fast. great product and price.


Excellent product and easy to install works great




No issues delivered on time and everything in the package as expected.


Easy to install, works as it should.


As expected


Ask the Experts about this CURT Trailer Wiring

  • Is There a Wire that Runs to the Vehicle Battery to Install the Curt Wiring Harness # C56190
    Yes, there is a wire from the Curt Wiring Connector part # C56190 that will need to be run to the positive terminal of your vehicle battery on your 2014 Acura MDX. This doing this protects the delicate taillight circuits of your vehicle. Instead of powering the trailer taillights with your vehicle taillight circuits, this unit will pull all the amperage needed from your vehicle battery and will only use your vehicle taillight circuits as signal wire. I attached an FAQ article on routing...
    view full answer...
  • Routing the Power Wire for a Trailer Wiring Harness on a 2009 Honda Odyssey
    I think you are looking at the Expert question and answer pages for the Curt trailer wiring harness # C56190. The link is on the right hand side of those pages and it is called Routing the Power Wire for a Trailer Wiring Harness. I have also included it here to the right hand side of the page.
    view full answer...
  • Tow Bar Wiring Adapter Recommendations
    It sounds like you have a 5-way connector on your RV like the part # PK11502 or something similar and are looking for a way to convert it to a 4-way to connect to the tow bar wiring of your towed vehicle. To see all of the tow bar wiring adapters we offer check out the link I provided. If you do not see what you need email me back and I will help you find what you need. If you could send me pics of what each of the connectors look like that would be very helpful.
    view full answer...
  • Brake Light Wire on 2015 Mercedes GLK 350 to Install a Trailer Wiring Harness
    In some situations on vehicles with multiplex wiring systems like your 2015 Mercedes GLK 350 the brake light signal can only be obtained at the center high mount stop lamp. So if you cannot find the right circuit at the tail lights then try the third brake light at the top, center of the rear of the vehicle.
    view full answer...
  • Trailer Wiring Harness Recommendation for a 2015 Audi Q5
    The Curt Wiring harness part # C56190 that you referenced has been confirmed by Curt as a fit for your 2015 Audi Q5. This is a hardwire install harness so the connector that you mentioned won't be an issue. You will need to test the wires of the taillight connectors to determine function so that you can wire the # C56190 to them appropriately. As long as you install the harness correctly it will not interfere with the side assist sensors at all.
    view full answer...
  • Trailer Wiring Recommendation for a 2014 Audi Q5
    The recommended trailer wiring for the 2014 Audi Q5 Curt has been listed as the # C56190. This harness is not designed for pulse width modulation vehicles so that would mean that your vehicle does not have PWM.
    view full answer...
  • How is the Curt Powered Tail Light Converter Installed on the Vehicle
    The Curt Powered Tail Light Converter, # C56190, will wire directly to your vehicle's battery. The 12 volt wire will be used to power your trailer lights rather than running off your car's lighting circuit and causing strain on you vehicle's lighting circuit. The wire kit will include a fuse holder and 10 amp fuse that will be wired inline from the battery to the converter. The attached diagram shows the typical installation for the Curt Wiring Harness, C56190.
    view full answer...
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  • Troubleshooting Powered Converter Box Where Trailer Brake Lights Are Always On
    It's possible that the converter box on your Curt # C56190 has gone bad, but typically something like this is caused by a short in the system that would need to be fixed to avoid the issue again. From what it sounds like, I believe this can be isolated to the tow vehicle and I recommend that you begin by checking the wiring for any damage that might be visible. I also recommend checking the trailer plugs and cleaning them off so that they're free of dirt, debris and corrosion. If you can...
    view full answer...
  • Recommended Trailer Wiring Harness for 2011 Audi S4
    There is not a harness that plugs into your factory wiring without splicing so I recommend the Upgraded Heavy Duty ModuLite Circuit Protected Vehicle Wiring Harness with Installation Kit # 119190KIT. This will have the amperage you need whether you pull a trailer with incandescent or LED lights. I've attached a video of this installation on a Q7 to assist with the installation. I've also attached the installation instructions to help.
    view full answer...
  • Locating Tail Light Wires on a 2013 Infiniti JX35 to Install the Curt 3 Wire to 2 Wire Converter
    The Curt Universal 3 Wire to 2 Wire Harness, # C56190, that you purchased was designed to connect directly to your vehicles tail light circuits. This wiring harness was not designed to connect to a specific box or connector on any particular vehicle. You should be able to access the tail light circuits on your 2013 Infiniti JX35 either directly behind the tail light assemblies, or you may be able to find the behind the trim panels in the rear cargo area on the driver and passenger side...
    view full answer...
  • Replacement Trailer Wiring Harness for a 2012 Chrysler Town and Country
    The converter boxes are not available by themselves so the whole harness will need to be replaced on your 2012 Chrysler Town and Country. I recommend # 118534 because we hear about less issues with the Tekonsha brand. If your original wiring harness used a power wire then you can reuse it so you won't have to run another power wire to the battery for the new kit.
    view full answer...
  • Availability of Valley Tail Light Converter
    We do not carry any Valley products (they are no longer in business) but we do have a large selection of similar tail light converters available. I specifically recommend the Curt Powered Tail Light Converter # C56190. This powered converter features the 6 wires into the converter and 4 wires coming out to the built-in 4-Way flat connector. It has a maximum amperage of 7.5 amps for the tail lights and 4.2 amps for the stop/turn lights. I have attached a couple video demonstrations on...
    view full answer...
  • Most Reliable Trailer Wiring 4-Way Kit for 2014 Kia Sorento
    The modules of the trailer wiring for your 2014 Kia Sorento are not replaceable as they are not available individually. Instead you'd need to replace the entire kit with the # 118269 which is a confirmed fit and our most reliable option.
    view full answer...
  • Curt # C56190 Taillight Converter for 2013 Audi Q5
    I'm not sure which video you're speaking of, but I've confirmed with Curt that the # C56190 is indeed the correct taillight converter for your 2013 Q5. The # 55151 wiring kit is also needed to make the fused connection at the battery. I've provided you with a diagram showing an install diagram. There should be 5 wires exiting the 'input' side of the converter, a white ground wire, brown for running lights, yellow for left turn, red for brake light, green for right turn and black to the...
    view full answer...
    Image 1 for
  • Converter Needed to Separate Turn Signal From Brake Light Circuit
    We've got exactly the converter you're needing, part # 118158. I've provided you a diagram showing how to wire the converter. The converter will separate out the brake lamp signal from the turn signals. You'll also need to choose single function running lamp/brake lamp/turn signal lamps. If you'd care to see a product demonstration video, click the provided link.
    view full answer...
    Image 1 for
  • How to Add Dedicated Turn Signals to a Trailer with Combined Function Taillights
    I know what you are trying to do, and it is possible with the part # 118158. To add a separate turn signal on your trailer you would use the # 118158 to just tap into the trailer turn signal/brake light circuits but you would not interrupt the circuit that runs back to the taillight assemblies. This way the output side of the converter box will have the separate taillight signal for you to run to the additional turn signal and the rear taillights will still be combined. I attached a diagram...
    view full answer...
    Image 1 for
  • Will Trailer Wiring Harness from a 2012 Cadillac SRX Fit 2015 Ford Escape
    If you are looking for the most economical way to add trailer wiring to the 2015 Ford Escape that you are purchasing, you can use the Curt 3 Wire to 2 Wire Converter, # C56190. The Escape is going to require a heavy duty converter like the one in part # C56190 so we can not recommend reusing the wiring harness from your 2012 Cadillac SRX. You may want to consider going with a plug-in option like the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, # 118566. There isn't...
    view full answer...
  • Taillight Converter for 2010 Harley Davidson to Tow Trailer with Combined Stop/Turn Signals
    If you need the actual converter to combine the bike's separate stop and turn signals into a combined signal to match your trailer, then you can use Curt 3 Wire to 2 Wire Converter # C56190. This converter takes in separate stop and turn signals and outputs combined signals on the yellow and green (L & R) wires. You will also need Powered Converter Wiring Kit # 55151. If your hog has an existing wiring harness that has a 5-pole flat type vehicle connector and your trailer has a 4-pole...
    view full answer...
  • Right Trailer Turn Signal Stays On Using Curt T-Connector On 2008 Chrysler Town and Country
    I concur, it does indeed sound like you have a faulty control module. That said, the control modules are not replaceable by themselves so you will need to obtain an entire new trailer wiring harness unfortunately as you are out of the warranty period as well. For replacement, I would actually go with the T-One Vehicle Wiring Harness part # 118552 as we tend to find that this brand makes the most reliable wiring products therefore the control module will last longer. The good news is that...
    view full answer...
  • Will Trailer Taillight Converter on 2018 Mercedes-Benz Sprinter Affect Blind Spot Detection System
    If you install your light bar using the vehicle's taillight circuits, it shouldn't interfere with with the blind spot detection system on your Sprinter. Can I make a suggestion? Instead of a hardwired harness like the # C56190 you'd looked at, I'd recommend the Tekonsha # 118649 instead. The harness plugs inline between the vehicle's taillight wiring harnesses and taillight assemblies, and you'll need to run the power wire to the positive battery terminal. This will make for an easier...
    view full answer...
  • 2014 Mercedes Benz GLK 250 Bluetec Wiring Harness Recommendation
    Although they are not specific to your 2014 Mercedes GLK-250 BlueTec I did attach a set of installation instructions for the Curt Wiring Harness part # C56190 that you referenced to the right that will give you a good idea on how to install it on your vehicle.
    view full answer...
  • How To Separate Turn and Brake Signal On Trailer
    I do have an option for you to keep the brake lights and turn signals on the trailer separate however the Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector part # C56190 is not going to work that way. I recommend Curt 2-To-3-Wire Tail Light Converter part # C56196 to separate the functions. The input side, white wire is ground, green is the combined right turn signal/brake light and yellow is the left turn signal/brake light. On the output side you have the green for...
    view full answer...
  • Which Trailer Wiring Harness from Curt was Designed for 2017 Ford Transit T250
    Curt has a custom fit trailer wiring kit that fits your 2017 Ford Transit T250 with the part # C56327 which installs easily by plugging in line with the taillight connectors but they don't have the # C56190 listed as a fit for your vehicle so we don't have specific install instructions we can recommend that have been tested. Since your vehicle has combined trailer wiring the red wire being grounded is the correct approach but you might check the connections of the other wires as well.
    view full answer...
  • Audi Q5 2015 Trailer Wiring Installation
    The best installation instructions I can give you for installing the # C56190 on your 2015 Audi Q5 would be to use a circuit tester like part # PTW2993 to test the wiring harness of the taillights you have on your vehicle and then wire up the # C56190 accordingly by function. Here's how the converter will wire to your taillights. Converter Brown Wire: Tail Light Circuit Converter Yellow Wire: Left Turn Circuit Converter Red Wire: Brake Light Circuit Converter Green Wire: Right Turn Circuit
    view full answer...

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