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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
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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. 1-833-496-1390 to order CURT custom fit vehicle wiring part number C79KR or order online at Free expert support on all CURT products. Guaranteed Lowest Price 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 (4)
  • Q & A (0)
  • Videos (1)
  • Photos
  • Why etrailer?

CURT Custom Fit Vehicle Wiring - C79KR

  • Trailer Hitch Wiring
  • 4 Flat
  • Converter
  • CURT

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

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

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Review of Curt Custom Fit Vehicle Wiring - Trailer Hitch Wiring - C79KR

Michael: Hi there. I'm Michael with Today, we're going to take a quick look at the CURT T-connector vehicle wiring harness. This wiring harness is going to connect to your vehicle, and it's going to allow you to send your light signals back to your trailer, so that as you're pulling it, other drivers can see your turn signals, brake signals, those sort of things, to make sure that you're nice and safe while you're driving. So, it is going to be an important component of your towing setup. Now, this is a very easy to install kit.

If you've got any sort of mechanical aptitude at all, I think this is going to be very easy to get installed. It is going to fit your 2016 through 2019 Volkswagen Passat. So, if you've got a Passat, this will work for you. This is going to install right behind your taillights.So, you will have to get in to your rear storage compartment, get access to the backside of your taillights. And then basically, all you have to do is remove the plug that's currently plugged into your taillights, plug that into the wiring harness here, and then use the other side and plug that into your taillights.

So, that will then reconnect to that circuit, so your taillights will operate as normal. And then, the signal will also be sent out to your trailer. It's very easy to get installed. You're not going to have to worry about wiring, splicing, or anything like that. So, no risk of damaging your vehicle's wiring.

The most difficult part is probably just going to be running this extra cord from the back of your vehicle up to the front, where you're going to hook it up to the battery.Just try to stay away from anything hot or moving. And, of course, crawling underneath your car, the whole span could be difficult, depending on what your setup is like. But, they've got everything included here for you to get this all installed, including instructions to help you to install it correctly. But, it's a very simple process, definitely something that I would encourage just about anybody to try for themselves. So, this is a pretty solid box.

They do use surface-mount technology, so it's going to be pretty durable. You're not going to have to worry about those connections coming off, causing any problems like that. This wiring can live in your rear cargo area, just sitting off to the side somewhere, so that when you are ready to tow your trailer, you just run the wire out the back. You can close the back hatch on it.This does have a dust cap included, so that you can protect it from dust if you're not using it, which typically you will just store it in the vehicle. But, if you do want to have it out, you can have that dust cap on there. This is going to give you a max amperage of five amps per circuit, for your stop and turn signals, and seven amps per circuit for your taillights. It also comes with a limited one-year warranty. So, if you've got that vehicle that you're wanting to pull a trailer with, I think this is going to be a great option for you. Very easy to get installed yourself. You're not going to have to pay a mechanic to do it, or anything like that. And everything that you need is included in the kit. So, that's going to complete our look for today. Again, I'm Michael with I hope this video has been helpful in deciding if this is the right kit for you, or not. And we'll see you next time.

Customer Reviews

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

Average Customer Rating:  5.0 out of 5 stars   (4 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.


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.




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

  • 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...
  • 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...

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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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