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Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

Item # C79KR
Our Price: $75.28
You Save: 40%
Custom Fit Vehicle Wiring

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Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring. Powered converter reduces strain on wiring system and is made using SMT to ensure superior performance. 1-800-940-8924 to order CURT custom fit vehicle wiring part number C79KR or order online at Free expert support on all CURT products. Great prices and Fastest Shipping for Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector. Custom Fit Vehicle Wiring reviews from real customers.
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  • Reviews (7)
  • Q & A (0)
  • Photos

CURT Custom Fit Vehicle Wiring - C79KR

  • 4 Flat
  • Trailer Hitch Wiring
  • CURT
  • Converter

Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring. Powered converter reduces strain on wiring system and is made using SMT to ensure superior performance.


  • 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)
  • Connects quickly and easily
    • Locate connection points in rear cargo area
    • Plug in T-connector
    • Run hot lead to car battery
  • Includes a powered tail light converter that connects directly to your battery to avoid overloading your electrical system
  • 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
  • Comes with dust cap for 4-way flat connector


  • Maximum amperage:
    • Stop/turn lights: 5 amps per circuit
    • Tail lights: 7 amps per circuit
  • Limited 1-year warranty


This custom-fit T-connector plugs into your vehicle's wiring harness, which is located in your rear cargo area. You will have to remove the trunk floor covers, storage trays, scuff panel, and interior side panels to access this harness. Once you've plugged in the T-connector, run the hot lead up to your car battery. Connect the lead to the included fuse holder, and then connect the fuse holder to the positive terminal on your battery.

Once installation is complete, the 4-way connector will be stowed in an out-of-the-way location within your cargo area.

It is recommended that you use a small amount of grease on all electrical connections - the plugs on your automobile and the 4-pole connector itself - to help prevent corrosion.

Powered Tail Light Converter with Surface-Mount Technology

A tail light converter is built into this T-connector. 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.

56440 Curt T-Connector - Surface Mount Technology - 4 Wire

Installation Details C79KR Installation instructions

This Product Fits The Following Vehicles

Customer Satisfaction Score:

Customer Reviews

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - C79KR

Average Customer Rating:  4.7 out of 5 stars   (7 Customer Reviews)

Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring. Powered converter reduces strain on wiring system and is made using SMT to ensure superior performance.


very easy to install


Watch the instruction video and this turns to light work. It is time consuming. Harness works and is of simple design making your life as easy as possible


Works great. Running the power wire takes the most time. The rest is plug-n-play.


2018 Volkswagen Passat




See what our Experts say about this CURT Custom Fit Vehicle Wiring

  • Recommended 4-Way Trailer Wiring Harness to 7-Way Trailer Adapter and No Drill Mounting Bracket
    The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # C79KR for 2016 - 2019 Volkswagen Passat models will connect to a 7-way using an adapter like the Hopkins Adapter 4-Pole to 7-Pole and 4-Pole # 37185. You simply will connect the 4-way trailer connector and then ground the adapter to your vehicle using the white wire with ring terminal. If you want the other 7-way functions, you will need to use a kit like # 5506 to add the 12V power and brake controller....
    view full answer...
  • Needing a Wiring Harness to Fit a 2017 Volkswagen Passat SE
    I have the answer for you. For your 2017 Volkswagen Passat the Tekonsha T-One Wiring Harness, # C79KR, is the confirmed fit for your SE model. The connector will plug in to your Passat's factory wiring and will provide a 4-pole flat connector for your vehicle. The harness will include a powered convertor that will ensure that your Passat wiring will match the trailer you will be wanting to tow.
    view full answer...
  • Will Hands-Free Trunk Feature on 2017 VW Passat Affect Installation of EcoHitch 306-X7317
    Although the EcoHitch could interfere with the hands free trunk feature on you 2017 VW Passat or possibly prevent it from working, the fact that the vehicle has that feature won't affect the fit of the # 306-X7317 EcoHitch. The install is pretty involved, as you can see from the video I've linked for you. If you'll be using the hitch for towing purposes, you'll also need a trailer taillight wiring harness like # C79KR if the vehicle has LED taillights or # 118721 if it has incandescent...
    view full answer...
  • Does Draw Tite Hitch # 24880 Fit 2017 Volkswagen Passat SEL with Technology Package
    Yes, the Draw Tite hitch part # 24880 that you referenced does fit your 2017 Volkswagen Passat SEL with the technology package. However, the hitch will interfere with the Hands-free Easy Open Trunk option and functionality may be very limited or possibly lost. You'll run into the same issue with the Curt and EcoHitch trailer hitches that fit your 2017 Passat SEL as well. If you need trailer wiring you'd want the Tekonsha kit part # C79KR which is a confirmed fit and is also compatible...
    view full answer...
  • Recommended Hitch and Towing Accessories for 2019 Volkswagen Passat
    For what you're using the hitch for, you'd be fine with a low-cost option such as the Draw-Tite Class I receiver, part # 24880 but if you were planning on also using the hitch as a mounting location for a bike rack or a cargo carrying tray, you might be better off going with a 2 inch receiver like what would be provided by the EcoHitch # 306-X7317. There are many more accessory options that are compatible with a 2 inch receiver, so if you were going to use the hitch for something other...
    view full answer...
  • Correct Trailer Wiring Harness for a 2017 Volkswagen Passat SEL with LED Taillights
    The correct Vehicle Wiring Harness with 4-Pole Flat Trailer Connector for your 2017 Volkswagen Passat SEL with LED taillights is part # C79KR. This harness is confirmed to fit Passats with or without LED taillights.
    view full answer...
  • Will The Maximum Tongue Weight on a 2018 VW Passat Increase With Curt Trailer Hitch Receiver?
    Sorry Brian, installing the Curt Trailer Hitch Receiver # C11234 is not going to increase your allowable tongue weight on your 2018 VW Passat SE. The maximum weight capacity give by the vehicle manufacturer can not be increased because the receiver has a higher weight capacity. This is all to common as the aftermarket likes to build their products to be stronger than the vehicle can handle to help ensure their product is safe to use. I always recommend having a 4-Way # C79KR installed...
    view full answer...
  • No Brake Lights with Taillights On Trailer Wiring Harness
    This is a pretty common sign of an insufficient ground. The system has a good enough ground for the normal lights but when you turn on the running lights which require more power, it shuts the system down. I recommend simply choosing a new ground for the converter. This should be a bare metal spot on the body or frame.
    view full answer...
  • Hitch Recommendation for 2019 VW Passat With Easiest Install Process
    If it were my Passat, I would go with the EcoHitch # 306-X7317 because of the options it gives for accessories. The install is more involved than others, but I think this is the best choice. You'll only install the hitch once, but you will use it for much longer and will find the extra effort is well worth it. There are 3 different hitches that are confirmed to fit your 2019 VW Passat Wolfsburg edition, Draw-Tite Sportframe Trailer Hitch # 24880, the Curt Trailer Hitch Receiver # C11234,...
    view full answer...
  • Trailer Hitch Receiver for Bike Rack on 2017 Volkswagen Passat R-Line
    I recommend using the EcoHitch Hidden Trailer Hitch Receiver # 306-X7317 over the Curt # C11234 due to the weight that you're looking to carry. The EcoHitch bolts into the chassis rather than clamping around the frame like the Curt on your 2017 VW Passat. I recommend installing the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat # C79KR while your are installing the hitch. This will allow you to have auxiliary taillights # C53201 that can be placed on your bike rack since your...
    view full answer...
  • Does the Tekonsha T-One Vehicle Wiring Harness and Connector 1C79KR Come With a Mounting Bracket
    The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector Item # C79KR does not come with a mounting bracket. You can use the Mounting Bracket # 18144 as well as a No-Drill Mounting Bracket Short # 18140 or Long # C57202 for an easy installation that does not require you to drill into your trailer hitch receiver. I have attached a video of these two products being installed that you can reference.
    view full answer...
  • How to Determine Towing Capacity of 2018 VW Passat
    The best way to determine what your vehicle can tow is by looking at its owner's manual. Unfortunately, VW manuals are hard to find online unless you own the car already so I don't have a way to look at it for you. From the research I did it seems that the max towing capacity of your 2018 Passat is 1,000 pounds which sounds pretty likely. I recommend checking your manual to be certain though. Once you know how much you can tow you'll need the parts to do it. The hitch I recommend is...
    view full answer...
  • Hitch Fit for 2020 Volkswagen Passat
    According to Curt, their # C11234 will fit all models of the 2020 Passat, with the exception of models equipped with the hands-free truck feature. If you'll be using the hitch for light-duty towing, you'll also need a trailer wiring harness like # C79KR(if you have incandescent lights) or the , a ball mount like # C45521, a hitch pin like # PC2 and a 1-7/8 inch hitch ball like # A-80 or a 2 inch ball like # A-82. I've linked to an install video for the hitch.
    view full answer...
  • How to Find Out if a 2016 Volkswagen Passat SE has a Towing Capacity and How Much It Is
    If your 2016 Volkswagen Passat SE has a towing capacity it would be listed in the vehicle owner's manual. Volkswagen used to provide access to the owner's manuals online but now in order to view the manual online you have to put in a valid VIN for that vehicle. But your owner's manual would be the place to check for towing information. If you decide to go with Draw-Tite trailer hitch # 24880 the recommended ball mount is # 3590. For a compatible ball you can use # 19256 for a 1-7/8 inch...
    view full answer...

Do you have a question about this Custom Fit Vehicle Wiring?

Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Wilson B
Updated by:
Wilson B
Employee Kristina F
Written by:
Kristina F
Employee Michael B
Installed by:
Michael B

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