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FITS 2017 Chevrolet Sonic
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 # C56372
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Custom Fit Vehicle Wiring
Confirmed to Fit
2017 Chevrolet Sonic

LS models

LT and Premier

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C56372 - Custom Fit Curt Custom Fit Vehicle Wiring
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Call etrailer.com at 800-298-8924 for expert service. We are your Chevrolet custom fit vehicle wiring experts, and offer a lowest price guarantee. etrailer.com carries a complete line of Curt products for your Chevrolet Sonic 2017. Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector part C56372 from Curt can be ordered online at etrailer.com. Complete custom fit vehicle wiring installation instructions and technical support.
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2017 Chevrolet Sonic - Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

  • Trailer Hitch Wiring
  • Curt
  • 4 Flat
  • Converter

Quickly and easily install a 4-way trailer connector on your Chevrolet Sonic 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 tail light converter that connects directly to battery to avoid overloading vehicle's 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: 7.5 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 rear scuff panel, trunk floor coverings, 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 trunk.

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.

56372 Curt T-Connector - Surface Mount Technology - 4 Wire

Installation Details C56372 Installation instructions

California residents: click here

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 Curt Custom Fit Vehicle Wiring - Trailer Hitch Wiring - C56372 Review

Speaker 1: Today we're going to take a look at the Curt T Connector vehicle wiring harness with the four-way flat trailer connector. This is a custom fit part. It is designed to fit the 2017 Chevrolet Sonic and on a custom fit part, I always like to recommend for you to go to our website, use our fit guide, put in your year and model vehicle and it'll show you if this'll work for your application.Now this harness will provide this four way flat trailer connector at the back of your vehicle, it'll power your trailer signal lights. It is compatible with five pole, six pole and seven pole adapters that we do sell separately on our website and this full assembly does connect very quickly and easily. Basically just locate your connection points in the rear cargo area. Take these "T" connectors, you'll plug these into one on each side.

One on the driver's side, one on the passenger's side. Ground your white wire and then you have your power wire right here that you'll run to your vehicle's battery.Now this harness does include this taillight convertor, this black box right here. This'll connect directly to the battery to avoid overloading your vehicle's electrical system, and it is constructed using SMT Technology which is Surface Mount Technology, gives you more consistent, reliable performance, helps maximize your trailer light yield and intensity while producing minimal heat and it ensures superior operation in rough road conditions. Does also come with this nice dust cap or cover for your four way flat connector. Basically what you can do with that is just attach it to plug and you can leave it attached if you like and then what you'll want to do is when you're not plugged into your trailer, just put that cap over those terminals and it'll protect 'em from the elements or from any damage.

This part is made in the USA.Few specs on this. The maximum amperage for the stop and turn light circuits is 5 amps per circuit. For the taillights, it's 7.5 amps per circuit. Now this kit does come with everything shown here on the table and just briefly how you'd install this. Again, you'd go to the rear cargo area of your vehicle, gain access to behind the taillights and you'll start on the driver's side.

You unplug the harness from your taillights, plug this T connector in between there. For the passenger's side, it'll be the one with the green wire and the length of wire. This'll run over to the passenger's side and you'll do the same, connect this between the harness and the taillights.Once those are all connected, you'll want to take your convertor box right here and you don't want that bouncing around so you'll want to attach that to a good flat surface and they do include this piece, a double face, that you can put on there and attach it to a nice clean surface. Once that's done, you'll run this length of wire with the four way on the back out towards the rear of the vehicle to plug into your trailer and the two remaining wires, the white wire with the eyelet on it, that's for good clean ground. You want to connect that to a good clean ground if there's one nearby.

If not, they do include the grounding screw that you can make your own ground.The last wire, the black wire is your power wire. That'll need to run to you vehicle's battery and they do give you this extra length of wire to run that up to your vehicle's battery and the connector so you take one of the butt connectors, put it on there, connect it to one end of this length of wire and then run this all the way up towards the front. When you get to the front, you don't want to connect this other end directly to the other battery. You want to run it through this end line fuse holder. So take the other connector, connect it to one end of the fuse holder just like that and then on the other end, you'll take the eyelet connector and connect that and then this is what'll connect to the battery. Once that's all connected, open it up, take your included 15 amp fuse, stick it into the fuse holder, put the cap back on there and your system will be already to go.Now if you notice, they do include some extra cable ties to take up any slack in the wiring and they do give you a nice set of detailed instructions that'll describe how to install it and even show pictures of how the connections are.But that should do it for the review on the Curt T Connector vehicle wiring harness with the four way flat trailer connector.

Customer Reviews

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - C56372

Average Customer Rating:  5.0 out of 5 stars   (1 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.

- C56372

This is the second wiring harness I have purchased and just like the first one the connectors fit perfectly. My only down side is the length of the wire to the passenger side. It was only long enough to reach halfway, this wasn't a big problem it is only one wire and easy to extend. 470245


Ask the Experts about this Curt Custom Fit Vehicle Wiring

  • Comparing Trailer Wiring Harnesses for a 2017 Chevrolet Sonic RS/LT Hatchback
    You are correct in that both the T-One Vehicle Wiring Harness part # 118755 and the T-Connector Vehicle Wiring Harness part # C56372 are a fit for your 2017 Chevrolet Sonic RS/LT Hatchback. There are few differences between them as they both plug in behind the tail lights without any cutting or splicing involved. They are essentially just two different manufacturers version of the same product. They both have the same purpose and will plug into the same connector on the vehicle which is...
    view full answer...

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Info for this part was:

Edited by:
Lindsey S
Installed by:
Jeff D
Updated by:
Sarah W
Updated by:
Kristina F
Updated by:
Isabelle B
Written by:
Ronnie R

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