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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
2014 Mazda 6
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CURT

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

Part Number: C56251
In Stock
$96.47
Retail:$166.95
You Save: 42%
Custom Fit Vehicle Wiring
Not Confirmed to Fit

2014 Mazda 6

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In Use/Installed

etrailer Installation
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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 C56251 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 (37)
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CURT Custom Fit Vehicle Wiring - C56251

Highlights

  • Custom Fit for Your Vehicle: Works with your vehicle's wiring
  • Plug-and-Play Install: T-connectors plug into factory tail light ports—no wire cutting.
  • Ready for Trailer Lights: 4-way flat gives power for tail, turn, and brake lights.
  • Protected Circuitry: Powered converter draws direct battery power to shield vehicle wiring.
  • Clean Grounding: Dedicated white ground wire ensures solid, corrosion-free signal paths.
  • Simple Power Hookup: Single fused lead connects to battery for reliable trailer lighting feed.

Features to know about

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

Wiring up trailer lights doesn’t need to be complicated. The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector plugs directly into the factory tail light connectors, so you don’t have to trace or splice any wires. It’s a clean setup that keeps your vehicle’s wiring intact while giving you a reliable 4-flat connection for running, turn, and brake lights.

Comparison image showing Curt T-Connector vehicle wiring harnesses with 4-pole flat trailer connectors, highlighting connectors, wiring, and converter boxes for different vehicle applications.

Reliable Power for Trailer Lights: Built-In Powered Converter

Some vehicles need extra help powering trailer lights, and that’s where the powered converter comes in. It pulls power straight from the battery instead of the tail light circuit, keeping the vehicle’s electrical system protected and preventing overloads. The included fuse holder connects to the positive terminal to complete the circuit safely.

Trouble-Free Connection Every Time: Secure Factory-Style Plugs

Loose or corroded connections are common causes of trailer light issues. This harness uses factory-style connectors that click firmly into place for a solid connection. The terminals match the vehicle side exactly, reducing the chance of bent pins or incomplete contact that could cause signal loss.

Clean Install with Hidden Wiring: 4-Flat Connector at the Ready

Once installed, the wiring stays out of sight behind panels with only the 4-flat connector exposed when you need it. It’s a neat, low-profile setup that looks factory and keeps wires protected from dirt and corrosion. When not towing, just stow the flat plug inside or near the hitch for quick access next time you hook up the trailer.

Specs

Electrical Specifications

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

Note

This will not affect how the tail lights on your vehicle operate.

56251 Curt T-Connector - Surface Mount Technology - 4 Wire

Similar to Hopkins HM11143795 and Tekonsha 118526

Installation Details C56251 Installation instructions

This Product Fits The Following Vehicles




Customer Satisfaction Score:

Ratings & Reviews

4.6

37 reviews
5 Stars
(27)
4 Stars
(8)
3 Stars
(1)
2 Stars
(1)
1 Star
(0)
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by:
The hitch was very easy to install. The wiring was a challenge, but we got it done.
by:
Perfect fit, easy to install
by:
2014 Kia Sportage
This wire kit was pretty easy to install; the directions were very detailed and accurate. The only issue I ran into was there is a point in the instructions where you're running wires through a grommet that is way too small for the connectors and the instructions reference a new grommet that is not part of the kit. I just cut the old one to fit the new wires th through the side and it was all good. Routing the 12v wire was pretty simple; I had my car backed up on a pair of ramps and ran the wire along the brake and fuel rail on the driver side under the car. I punched this one up through that grommet too to plug in at the module. I don't use butt connectors; I always solder and heat shrink. Personal preference. In all, this was a straight forward and simple install.
Flash profile picture

Flash

11/1/2017

The hitch and wiring are still going strong! Ive had no issues at all.

by:
Kia Sportage
This was actually the third one I installed on this vehicle. The first installation went well, had good instructions. Got all finished and the trailer turn signals and brake lights were so dim that they could barely be seen. Running lights were fine. After I checked all of my connections I called your customer service. I am a retired mechanic and I narrowed the problem down to the trailer module. They pleasantly surprised me when they agreed with my diagnosis. They sent me a new one and everything worked fine. Two years later the trailer pigtail got smashed in the Kia Sportage hatchback locking mechanism. It shorted out the trailer module. No fault of the product. Bought another one and installed it and has been working grat for the last year. Would have given it 5 stars if the first module module hadn't gave me problems. Shipping and customer service was great. Would recommend this product and Etrailer again .
by:
Installed the lighting kit when I installed the trailer hitch. The wiring harness worked perfectly and made pulling the trailer a breeze.
by:
The wiring harness great. The installation instructions and video are pretty accurate. The only problem I experienced was with reinstalling the grommet as the instructions could have been a little more detailed in this particular area. Otherwise, everything worked and installed easily
by:
2012 Kia Sportage
I love buying stuff from Etrailer.com. The listed products are the exact fit for my vehicle. The on line instructions make it very easy to install. I installed the hitch and wiring harness in just under 2 hours. I will buy stuff from this site again
by:
2011 Kia Sportage
The process of installing the Curt T-Connector Wiring Harness for my 2011 Kia Sportage went very well. I knew it would take quite a bit of time because of all the removal of the tail light, inner panels, etc. However, it is worth the time because of end result - a system that works, and appears almost factory installed. I highly recommend this product.
by:
Would have loved to have had a grommet made into wires on t connector that goes through trunk pan, down to factory harness that goes to left rear tail light.
Would gladly have spent a few more dollars for that bit to be pre made than having to cut the grommet and then patch it with the rtv sealant.
Besides that, install went very well.
by:
Easy to install. Instructions need to be slightly modified for the 2016 model year.
Missing replacement rubber grommet that was supposed to be included in the kit, otherwise okay.
by:
Worked as expected. A little difficult to install, even after watching the installation video.
by:
The wiring system worked exactly as described and the video guide was very helpful. Other than a few rusted bolts on my vehicle I installed the system with no issue and so far it has function and worked well within my expectations for a full year. Great product.
by:
2014 Kia Sportage
Arrived as scheduled. Package contained all necessary parts and in good condition.
Very pleased with the product . Harness was easily installed and works great. Glad I found this company
by:
Fit perfectly and as expected. Installation was a little challenging but the walk-through was very concise. Thank you. I will definitely order from etrailer again in the future.
by:
2016 Kia Sportage
Arrived sooner than expected. Haven't installed yet but looking over instructions appears they appear clear and easy to follow for me not having much knowledge on wiring anything. Great follow up with notification from etrailer. Install will hopefully be tomorrow.
by:
No harder to install than any other wiring kit fit perfectly instructions were great.
by:
2016 Kia Sportage
Wiring product was good but missing the grommet for the 2016 Sportage. Other then that pretty self explanatory
Kevin S. profile picture

Kevin S.

2/20/2018

Love your products. It is the only hitch I will purchase and your wiring kit was fantastic. I work at different campgrounds around the country, mainly east coast but I tell everyone about your products. Thanks for making products that actually fit and do what what consumers pay for. Love your stuff.

by:
2015 Kia Sportage
Great customer service!
by:
2015 Kia Sportage
looks like everything is there but box was damaged and hitch was sticking out
by:
Wonderfull web based support. Great attention and very polite attentive service
by:
All your product are well explained. I love the videos. Help out HUGE! It helps because so many makes and models. Give you a little idea of what you will encounter on the install.
by:
2015 Kia Sportage
Piece of cake install. 76 years old and did it right my myself.
My mantra: "I've done so much with so little for so long right by myself till I can do almost anything with nothing when I'm not even there."
by:
2016 Kia Sportage
Said the part was in stock and would be delivered within the week, ended up taking over a month.
by:
Still working great, no problems, easy install.
by:
Wiring was simple and easy to install
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Show More Reviews

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

  • What Do I Need to Add a 7-Way and Tow a Trailer With Brakes on a 2014 Kia Sportage?
    Hello John, Thanks for writing in! It all depends on whether your trailer has brakes. Either way, you'll start with the Curt T-Connector Vehicle Wiring Harness # C56251. This gives your 2014 Kia Sportage the 4-way flat that controls the trailer's turn signals, brake lights, and running lights. If your trailer does not have brakes and you just need the 7-way for your lights and 12V power, you will want the TowSmart 7-Way RV Style to 4-Flat or 5-Way Flat Trailer Connector Adapter # TS98RR....
    view full answer...
  • Curt Trailer Hitch and Wiring Harness Fits for 2016 Kia Sportage
    The correct Curt 2-inch Class III hitch for the 2016 Kia Sportage is part # C13120. This also fits the 2015 model year. This Curt hitch comes complete with all required installation hardware. I have linked the written instructions as well as an install video showing a 2015 model year. The only specialized tool needed is a torque wrench like # ALL944001 which will let you tighten the fasteners to the correct torque values. If you plan to move the hitch from one vehicle to another please...
    view full answer...
  • Troubleshooting Turn Signals After Installation of Curt 4-Pole Wiring Harness C56251 in Kia Sportage
    Thank you for your wiring harness purchase. The Curt 4-pole wiring harness kit # C56251 is a custom-fit product confirmed to fit your 2012 Kia Sportage. Since this installs using connectors that match those on the car there really is no wiring diagram per se, but the instructions are linked for you. Only the one power wire to the battery requires a spliced connection; this goes to the positive terminal via the included fuse holder. You do not mention whether it is the vehicle or trailer...
    view full answer...
  • Lighted Hitch Cover Remains On with Vehicle Lights Off
    A lighted hitch cover such as # CR-007 uses the same type of 4-pole wiring as a trailer that has basic lighting functions. This type of wiring set-up provides brake, turn and tail light functions. This 4-pole wiring harness, such as # 118526 and # C56251, will pass a very small amount of power even without any vehicle lighting functions activated. If you have a hitch cover that uses highly efficient LEDs instead of bulbs, like # CR-017, it may illuminate just from the small amount of residual...
    view full answer...
  • Recommended Trailer Hitch and Towing Accessories for 2012 Kia Sportage SX
    We'd be happy to help! Although the Draw-Tite # 75717 would fit for you, we'd recommend going with a US made product like the etrailer brand Class III hitch, part # e84KR. The hitch is compatible with the SX trim. If you'll be towing with the hitch, you'll also need a trailer wiring harness like # C56251. For a ball mount, use # D-28 and for a trailer ball, use # 40038 for a 2 inch ball or # C40002 for a 1-7/8 inch ball. I've linked to some install videos that you might find helpful.
    view full answer...
  • Troubleshooting Parking Lights Not Working With Curt Wiring Harness Installed On 2013 Kia Sportage
    I am sorry to hear you are having an issue with the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # C56251 installed on your 2013 Kia Sportage. Since only one function was not working with the harness installed, I recommend double checking that all of the pins in the connector that plug into to the factory driver side connector are not bent causing a the connection to not be complete. Also make sure that the connector clicks in to the factory connector. If...
    view full answer...
  • Could Converter be Bad of Curt 4-Way For 2016 Sportage
    Hey Paul, thanks so much for the purchase from etrailer of the Curt T-Connector # C56251 for your 2016 Kia Sportage. It isn't going to be the converter that is bad if just the turn signals don't work. It could be the ground being bad; make sure the ground to the driver side light is attached to bare metal surfaces and free of any paint, dirt or corrosion. Also check both your vehicle and trailer connectors for corrosion, which can be green or white in color - a build-up of corrosion can...
    view full answer...
  • Will the Curt Trailer Hitch Receiver # C13120 for the 2014 Kia Sportage Also Fit the 2015 Model
    I spoke with my contact at Curt and the Trailer Hitch Receiver, # C13120, for the 2014 Kia Sportage has been tested and it is also a fit for the 2015 model. This hitch has a tongue weight capacity of 350 pounds and a towing capacity of 3,500 pounds. Please keep in mind that Curt does require all non-trailer loads like bike racks and cargo carriers to be supported with a Trailer Hitch Support Strap, # 18050. Failure to properly support these loads will void your hitch warranty from CURT. As...
    view full answer...
  • Recommended 1-1/4" Hitch for a 2012 Kia Sportage SX
    Yes, it will! The Draw-Tite Hitch item # 36510 is confirmed to fit the 2012 Kia Sportage SX models with dual exhaust. Our installers have stated that the hitch comes in contact with the exhaust on the SX turbo models. This may result in the exhaust hangers needing to be bent to get the right amount of clearance. Other then that this hitch is custom fit and comes with all necessary hardware to complete the installation. The Draw-Tite Hitch item # 36510 is a class II hitch with a 1-1/4"...
    view full answer...

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Info for this part was:

Employee Lindsey S
Edited by:
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Video Edited:
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Employee Chris R
Video Edited:
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Expert Research:
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Installed by:
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Written by:
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Test Fit:
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