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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
1999 Chrysler 300M
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CURT

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

Part Number: C56376
35 Reviews | 8 Questions
In Stock
$69.60
Retail:$109.95
You Save: 37%
 Custom Fit Vehicle Wiring
Not Confirmed to Fit

1999 Chrysler 300M

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curt custom fit vehicle wiring trailer hitch plug-in t-connector harness with 4-pole flat connector
curt custom fit vehicle wiring trailer hitch plug-in
curt custom fit vehicle wiring trailer hitch end connector t-connector harness with 4-pole flat
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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 C56376 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 (35)
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CURT Custom Fit Vehicle Wiring - C56376

Highlights

  • Custom Fit for Your Vehicle: Works with your vehicle's wiring
  • Tow Without Factory Prep: 4-pole flat connector powers trailer running, turn, and brake lights.
  • Plug-and-Play Install: T-connector plugs inline with tail lights for a splice-free setup.
  • Reliable Power Feed: Powered converter draws directly from vehicle battery for stable lighting.
  • Protects Vehicle Wiring: Isolated circuit keeps trailer load off factory light wiring.
  • Clean Fit: Hidden harness design routes through factory grommets for a neat, factory look.

Features to know about

Installs Without Cutting or Splicing: Plug-In T-Connector Design

Wiring a trailer doesn’t have to mean cutting into factory wires. The Curt T-Connector Vehicle Wiring Harness uses plug-in connectors that match the vehicle’s existing plugs. Just snap them together and you get a clean 4-flat trailer connector ready for running lights, brake lights, and turn signals. No guesswork, no wire taps, just plug and go.

Protects Vehicle Electronics: Powered Converter for Safe Signal Transfer

This harness uses a powered converter that draws power directly from the battery rather than the vehicle’s lighting circuit. That keeps the factory wiring protected from overload and helps prevent blown fuses or signal interference. The separate power wire runs to the battery for a stable connection and reliable trailer lighting every time.

Keeps the Install Clean: Hidden, Vehicle-End Connector Setup

The harness design keeps things tidy by using a hidden, vehicle-end connector. It fits behind trim panels and factory grommets so the wiring stays out of sight and protected from road grime. You get a clean finish that looks like it came from the factory.

Ready for Everyday Towing: Standard 4-Flat Trailer Connector

The 4-flat connector gives you everything needed for basic trailer lighting—running, turn, and brake lights. It’s the standard plug used on most small and mid-size trailers, so you can hook up and hit the road without extra adapters.

Specs

Electrical Specifications

  • Connector type: 4-Pole Flat Trailer Connector
  • Converter type: Powered converter
  • Vehicle end connector: Plug-In
  • Application: Vehicles without factory tow package

Comparison image showing multiple Curt trailer wiring harness kits with labeled connectors and converter modules, illustrating differences in design and configuration for vehicle-specific trailer wiring.

Design and Installation

  • Installation type: Plug and Lead
  • Mounting style: Hidden
  • Product category: Trailer Hitch Wiring

56376 CURT T-Connector - Surface Mount Technology - 4 Wire

Similar to Tekonsha 118749

Installation Details C56376 Installation instructions

This Product Fits The Following Vehicles






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Ratings & Reviews

4.7

35 reviews
5 Stars
(29)
4 Stars
(3)
3 Stars
(1)
2 Stars
(1)
1 Star
(1)
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by:
Works like a charm.
by:
2017 Kia Niro
This trailer wiring installation was completed without too much fuss. The converter box wiring for the drivers side tail lights was very short and barely cleared the side panel when replacing. They should be about 8 or 10 inches longer.
by:
Kia Niro
Wiring the harness went as described in the attached directions. Directions were clear and concise. Wiring the 12-volt power cable on the Kia Niro... Not so fun :)
Mark L. profile picture

Mark L.

11/13/2018

After a year of using with trailer... no problems - works great!

by:
A few weeks ago, another driver was kind enough to tell me that my driver's side brake lights were out. They are LED, so I new it wasn't a bulb. I checked all of the fuses in the engine compartment fuse block and the interior fuse block as well. No blown fuses. I disassembled the interior panels (a pain) to access the custom-fit Curt Unit connectors and unplugged them, and plugged the OE tailight/brakelight connectors back together and the brake lights now work fine without the Curt Unit. As it turns out, the the warranty is for one-year and this Curt Unit failed after one-year and three weeks. etrailer won't do anything about it. I will be reaching out to Curt and hope that they make this right, otherwise I won't be buying any Made-in-Mexico Curt products ever again.
by:
Works fine in my 2020 Kia Niro EV. It was a little hard to route the wire from the rear to the 12v battery, but I was able to follow the brake lines and tie to them along the driver's side.

I only occasionally use the hitch as the Niro EV is not rated for towing, but since it shares the chassis with the hybrid - which is rated for towing small loads - the hitch fits perfectly.
by:
2019 Kia Niro
Perfect fit. I only wish the trailer plug was about 18" longer. I hid the box in the wall on the left side and ran the trailer cord back to the middle of the car and fished it through an existing hole in the bottom of the rear compartment. There was a rubber gromet in the hole, so I removed the gromet, cut a slit in it, ran the cable through the hole and reinstalled the gromet with the wire running through the slit. All is great, but cable is only sticking out about a foot. A little longer would have been nice.
by:
Good wiring fit. Eight more inches and would have been perfect to place control box anywhere I wanted.
by:
Extremely helpful instructions to install on my Kia Niro Hybrid Plug-in [PHEV]. LOOKS GREAT.
by:
Easy to order, good price and quick shipping. Helpful representative.
by:
2017 Kia Niro
2 day free shipping. Excellent customer service.
by:
2020 Kia Niro
I couldn't have installed it without your video. Thank You
by:
Works great, just don’t forget the ground attachment!
by:
Easy to hook up and worked well.
by:
Excellent products
Thank you
by:
Great prices. Excellent service and always in stock.
by:
Very fast!
by:
2021 Kia Niro
by:
2019 Kia Niro
Thank you, you guys are amazing and Shawn was outstanding
by:
2022 Kia Niro
by:
2017 Kia Niro
by:
good quality
by:
by:
by:
2019 Kia Niro
by:
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See what our Experts say about this CURT Custom Fit Vehicle Wiring

Do you have a question about this Custom Fit Vehicle Wiring?
  • Why Would Trailer Wiring Ground Wire have Voltage
    If there's a short on the trailer wiring to the frame of the trailer it can cause the ground wire to have voltage since it typically attaches to the trailer frame. So what I would recommend you do is go over the trailer wiring looking for any shorts to the frame and clean up as needed.
    view full answer...
  • Parts Needed To Tow a Camper With a 2020 Kia Niro Plug In Hybrid
    So I am going to start by warning you the owners manual for your 2020 Kia Niro Plug in Hybrid is very confusing as they don't specifically state any towing capacities but place a lot of emphasis on working with the parts manufacturer for towing capability. I would start by talking to your local dealer to also help with the input of what you are going to be able to tow. Also there is not a receiver specific to your PHEV but I do know some have installed the Curt Trailer Hitch Receiver...
    view full answer...
  • Trailer Hitch Capacity for 2017 Kia Niro
    We have a Class III hitch confirmed as a fit for your 2017 Kia Nira, part # C13329 which has a 3,500 lb trailer capacity. What you will need to do is check your owners manual for the towing capacity that Kia recommends. If it's lower than the hitch capacity you have to go by the lower rated figure as the overall capacity. For trailer wiring you then would want the part # C56376. If you wanted to do some towing you might be interested in etrailer ball mount kit # 989900. It comes with...
    view full answer...
  • Guide to Use When Routing Power Wire to Install Trailer Wiring on 2018 Kia Niro
    When routing the power wire of a trailer wiring harness up to the battery of a vehicle you want to make sure you avoid any pinch points or hot exhaust pipes. I wish we had a video that covered that but the best we have is a help article that has many tips and options for accomplishing what it is you are looking to do.
    view full answer...
  • Recommended Aftermarket Towing Products that Wont Void Vehicle Warranty on 2017 Kia Niro
    Adding a trailer hitch receiver like the Curt Trailer Hitch Receiver - Custom Fit - Class III - 2" # C13329 that bolts on to the frame of your 2017 Kia Niro will not void your warranty from Kia. You are covered under federal law. Consumers of aftermarket products are protected by the Federal Magnusson-Moss Warranty Act. The Act states that if something breaks on your vehicle and you take it in for warranty repair, the dealer must honor your warranty unless whatever modifications you have...
    view full answer...
  • Can Power Wire of Curt Wiring Harness that Fits 2020 Kia Niro Run to Vehicle Battery
    Yes, the Curt trailer wiring harness part # C56376 that you referenced can install by running the power wire directly to the battery like you mentioned.
    view full answer...
  • Trailer Wiring Harness Recommendation for 2017 Kia Niro
    The correct trailer wiring harness you'd want for your 2017 Kia Niro is the Curt kit part # C56376 which comes with connectors that were specifally designed for your vehicle. If you check out the install instructions I attached you'll exactly how all of the connections will need to be made.
    view full answer...
  • Wiring Harness Fits for 2018 Kia Niro
    The wiring harness fits we have for the 2018 Kia Niro, which include Curt part # C56376 and Tekonsha part # 118749 that you purchased, specifically exclude fitment on the plug-in hybrid version of the car. You'll see this notice on the linked page. If you have the plug-in hybrid we do not have a trailer wiring harness for it. I did check with my technical contact at Curt about installing wiring in your vehicle. He said that a Niro plug-in hybrid owner has reported using a 12V circuit for...
    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 Jeff D
Installed by:
Jeff D
Employee Jameson C
Expert Research:
Jameson C
Employee Adam R
Expert Research:
Adam R
Employee Jacob T
Video Edited:
Jacob T
Employee Wilson B
Updated by:
Wilson B
Employee Kristina F
Updated by:
Kristina F
Employee Isabelle B
Updated by:
Isabelle B
Employee Amanda M
Written by:
Amanda M

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