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  1. Custom Fit Vehicle Wiring
  2. CURT
  3. 4 Flat
  4. No Tow Package
  5. Trailer Hitch Wiring
  6. Vehicle End Connector
THIS ITEM IS NOT A FIT FOR
2004 Chrysler Sebring
CURT

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

Part Number: C56377
In Stock
$69.57
Retail:$110.95
You Save: 37%
Custom Fit Vehicle Wiring
Not Confirmed to Fit

2004 Chrysler Sebring

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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 C56377 or order online at etrailer.com. 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 (138)
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CURT Custom Fit Vehicle Wiring - C56377

  • 4 Flat
  • No Tow Package
  • Trailer Hitch Wiring
  • Vehicle End Connector
  • Plug-In
  • CURT
  • Plug and Lead
  • Powered Converter
  • Hidden

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.


Features:

  • 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 to ensure that your vehicle's wiring matches that of your trailer
    • Powered module 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


Specs:

  • Maximum amperage:
    • Stop/turn lights: 3 amps per circuit
    • Tail lights: 6 amps per circuit
  • Limited 1-year warranty


Installation

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 floor coverings, storage trays, rear scuff panel, and side trim panel 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 rear 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.


Because most trailers run on a two-wire system - wherein the brake and turn signals are carried on one wire - the separate brake and turn signals from your vehicle's three-wire system need to be combined so they are compatible with the wiring system of the trailer. This converter combines the brake and turn signal functions of your automobile so that they run on one wire to properly activate your trailer's tail lights. Note: This will not affect how the tail lights on your vehicle operate.


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.



56377 CURT T-Connector Vehicle Wiring Harness with 4 Pole Trailer Connector

Installation Details C56377 Installation instructions

This Product Fits The Following Vehicles



California residents: click here


Customer Satisfaction Score:

Ratings & Reviews

4.7

138 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.

by:
2020 Mazda CX-5

Great value, clear instructions on YouTube, two thumbs up



by:
2021 Mazda CX-5

The hitch is good quality and came with all the hardware and accessories needed.The same holds true for the wiring kit.



by:

Fast shipping. Straight forward installation. Everything works perfectly.



by:

I am not a professional but the instructions were more than sufficient to allow me to complete this installation!



by:

Easy to install - but a fair amount of disassembly required for the CX5 to install; but overall straightforward. I wired the power to a 12v plug as opposed to hardwiring to the battery, works great.



by:
2020 Mazda CX-5

Great product. Easy to install. Instructions were clean and understandable. Great price for comple kit.



by:

Easy installation and works great



by:
Mazda

Relatively easy to install if you know what you are doing. Works well in 2019 Mazda CX-5.

Brooke M. profile picture
Etrailer Expert

Brooke M.

5/20/2025

Glad the install went ok :) Have you caught any games this season? My nephews are at the game they're playing tonight :) Go Cardinals!



by:

etrailer is a great company. Excellent website and customer service! My small issue with my trailer hitch delivery is in regard to packaging. The cardboard carton was heavy duty, but it allowed the hitch to pierce the box in 4 places. A bit more padding inside might protect the ends from the mishandling of the shippers. Thanks again.



by:

Works great, routing the wire to the battery takes a bit of thinking.



by:

Went right in. Thank you for your excellent video.



by:
2019 Mazda CX-5

Package was complete and delivered fast.



by:

Well, I received the product in a timely manner, the install videos were very helpful and spot-on with how I needed to go about it, and the install went smoothly. Not simple by any means, but not too bad. However, after using this with my trailer 3 times, the running lights connection failed. (That's the brown wire, TM or "trailer marker" from what I can tell.) That's a big pain. I called Curt, and their service wasn't great. Seems to be blaming the trailer itself, and didn't really want to help. I got in touch with etrailer, and they were great. Helped me diagnose the problem, narrowed it down to a failure of this product, and got me set up with an advanced replacement under warranty, so I could pull out the bad one and put in the good one at the same time. So that's fine, but I'm only giving 3 stars, because the product failed me, and it cost me $XX to ship back the bad one, and about 2.5 hours of my time to swap it out. I think if the product works for you the first time, it's a 4 or 5 star product, but ymmv.

Josh profile picture

Josh

12/17/2023

It has been a year, and the new one I put in is still working great.



by:

The wiring harness I bought for my new hitch receiver fit my new 2020 CX-5 perfectly. Installation was easy, after figuring out how to disassemble the rear end of the SUV. The provided connectors mated perfectly with the vehicle connectors. Running a primary wire from the rear of the car to the battery was a bit of a pain; I'd recommend Curt find a way to tap into an appropriate conductor where the harness is being installed on future versions. Otherwise, everything worked perfectly, and when I got the car put back together the entire installation was invisible with the trailer connector pigtail stored in the spare tire compartment until needed. I'm completely satisfied with this harness, and recommend it highly.



by:

Product was easy to install. Great quality. Will continue to do business with Etrailer. Super fast shipping. Thanks

Randy profile picture

Randy

9/3/2023

Perfection, great quality products



by:
2020 Mazda CX-5

I installed this wiring harness myself on my 2020 Mazda CX-5. The instructional video was REALLY helpful. It showed in detail how to remove the interior panels to gain access to both taillights. The plug in T-Connectors were a snap to plug in. I chose to run the wire to the battery beneath the vehicle but inside the under sound proof panels so the wire is almost completely hidden from the elements. Works great and I would highly recommend this wire harness for a 2020 Mazda CX-5 (I think it works for earlier models as well)



by:
2021 Mazda CX-5

Super fast shipping. Ive ordered from them before. Always good service. Will continue to use this business AAAAA



by:
2018 Mazda CX-5

Not a bad install, it was kind of fun. But, in the video I watched they failed to mention the hardest part: running a 12ga, 12V wire from the battery to the rear of the car. It was a little scary drilling a hole in a brand new car's firewall to get the wire through (I did not want to run it under the car, that seemed much sketchier than running it through the interior.) But I hooked it all up, connected my trailer, and, perfect: all lights work great.



by:

I have had this for roughly 1 year. I have used the hitch with the wiring harness several times with no issue. It was all straightforward to install using the videos. I appreciate how the harness stays nice and clean tucked inside the car until I need it and then just put it away again.



by:

Product Review: all products arrived on time and in good condition. I have yet to inventory all the hardware but feel secure that all arrived complete. If not i Will be in touch,but feel this is unlikely given the service I received. This will be remembered and your service promoted to others. Thank You



by:
2020 Mazda CX-5

Purchased a Class III Hitch Receiver and wire harness for a 2020 Mazda CX5. Arrived within a couple of days, was well packaged and complete. Hitch installed fine and planning to install wire harness this weekend.



by:
2021 Mazda CX-5

The hitch and wiring harness I ordered came quickly and in perfect shape. Your instructional video was very helpful and made mounting a breeze. I have ordered parts here before and have never been disappointed and will continue to use etrailer in the future. Thanks.



by:
Mazda

Everything is easy to install except the line to the battery, and that just takes patience. I ended up temporarily removing the driver’s side protectors for an easier and cleaner run up my 2018 Mazda CX-5.

Scott profile picture

Scott

7/14/2019

One year out and Im still very pleased!



by:
2021 Mazda CX-5

Good Product, does what you need. It is time consuming...
Do Not like the fact they want you to hang the plug wires out the tail gate to plug in you trailer. There is a large grommet on the driver side that could be modified to get a good drop to the hitch. I split it and run the wires through then once it was back in place I siliconed it up.



by:
2019 Mazda CX-5

Great product, coupled with the very helpful videos from etrailer. The installation was very straightforward, and it seems to be working great in my 2019 Mazda CX-5. No complaints at all here, and for getting a 4 pin connector on my vehicle, I think I made the best choice.


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Info for this part was:

Employee Mike L
Expert Research:
Mike L
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Employee Lindsey S
Edited by:
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Video Edited:
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Employee Chris R
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Employee Cole B
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