bing tracking image
  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
2010 Dodge Caliber
etrailer Installation
We'll connect you with nearby partnered installers who know this exact setup.
CURT

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

Part Number: C56389
In Stock
$92.00
Retail:$154.95
You Save: 41%
Custom Fit Vehicle Wiring
Not Confirmed to Fit

2010 Dodge Caliber

Will this fit?

To see if this custom-fit item will work for you please tell us what vehicle you'll use it with.

zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.
By submitting this form, you understand and agree to our Terms of Sale, Website Terms of Use and Privacy Policy.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

In Use/Installed

etrailer Installation
We'll connect you with nearby partnered installers who know this exact setup.
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 C56389 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.
  • All Info
  • Reviews (2)
  • Q & A (0)
  • Photos

CURT Custom Fit Vehicle Wiring - C56389

Highlights

  • Custom Fit for Your Vehicle: Works with your vehicle's wiring
  • Tow Without Factory Prep: 4-way flat harness powers trailer lights when no tow package exists.
  • Plug-and-Play Install: T-connector plugs directly into vehicle wiring with no splicing.
  • Protects Vehicle Circuits: Built-in powered converter isolates trailer load from car wiring.
  • Clean Factory Fit: Hidden design routes wiring through trim for a neat, out-of-sight finish.
  • Ready for Common Trailers: Standard 4-flat connector works with most small-trailer lighting.

Features to know about

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

Wiring a trailer usually means tracking down wire colors and splicing into the factory harness, but this plug-in Curt T-Connector makes it simple. It connects directly to the vehicle’s existing tail light plugs to give you a 4-pole flat trailer connector with no cutting, no guesswork, and no need for extra parts.

Comparison image of Curt T-Connector Vehicle Wiring Harness with 4-pole flat trailer connector showing plug-in connectors and wiring leads.

Keeps Vehicle Wiring Protected: Powered Converter Safeguards Electronics

This harness includes a powered converter that isolates the trailer load from the vehicle’s sensitive wiring. It draws power directly from the battery instead of pulling it through the tail light circuits, reducing strain on the system and protecting delicate electronics from overload or feedback.

Clean, Hidden Setup: Factory-Style Connection with 4-Flat Lead

The harness tucks neatly out of sight with a hidden, factory-style connection that keeps things looking original. The 4-flat lead gives you running lights, turn signals, and brake lights in one compact plug that’s ready to connect to most small or mid-size trailers.

Ready to Tow Without a Factory Tow Package: Complete Vehicle-End Wiring

Even if your vehicle didn’t come with a tow package, this kit gives you everything needed on the vehicle end. It’s a full trailer wiring solution that creates a reliable link between the vehicle and trailer for safe, consistent lighting every time you tow.

Specs

Electrical Specifications

  • Maximum amperage:
    • Stop/turn lights: 3 amps per circuit
    • Tail lights: 6 amps per circuit

Warranty

  • Limited 1-year warranty

56389 Curt T-Connector - Surface Mount Technology - 4 Wire

Installation Details C56389 Installation instructions

This Product Fits The Following Vehicles




Ratings & Reviews

4.5

2 reviews
5 Stars
(1)
4 Stars
(1)
3 Stars
(0)
2 Stars
(0)
1 Star
(0)
Review Sort Icon
by:
Had it installed as part of hitch install with intent to tow small boat trailer, but never got a chance to take the boat out last year, so I never really tested the harness' operation in real life.
Chris profile picture

Chris

1/19/2024

Product failed in Dec. 2023left blinker started showing up to the car as burnt out, but replacing the bulb didnt fix it. Removing the passthrough connection from the vehicle harness to the lights. Discussions and diagnostics with Curt tech support conclude its a failed device, out of warranty. Disappointing, considering its been used for towing exactly 2 times.

Mike L. profile picture
Etrailer Expert

Mike L.

1/19/2024

@Chris The most common cause of a trailer wiring harness/taillight converter is a short circuit in the trailer wiring. You'll want to trace the taillight circuits back from the trailer connector to the trailer taillights, looking for pinched wires, loose connections or cracked/worn wire insulation that would allow the copper wire inside to short out to the trailer frame. You'll want to find and repair the short before using a replacement harness, otherwise they'll continue to fail. Hope that helps!
by:
2
2
true

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

  • Which Trailer Hitch Fits 2019 Buick Regal Sportback
    We do have a hitch for your 2019 Buick Regal Sportback GS but the Curt you mentioned does not fit the GS models. I checked with them just now to confirm this. Draw Tite offers the # 36652 though that fits all models of the 2019 Regal including your GS so it would fit and work well. If you need trailer wiring Curt has an easy to install and very reliable kit with part # C56389 that fits your vehicle.
    view full answer...
  • Trailer Hitch Receiver For 2018 Buick Regal TourX Using 2 Bike Rack and Cargo Carrier
    The Curt Trailer Hitch Receiver # C12173 is only available with a 1-1/4" receiver tube on your 2018 Buick Regal TourX. You can use a Curt Trailer Hitch Receiver Adapter # C45785 to allow you to still use your 2" hitch mounted accessories. The adapter does reduce the receiver capacity by 50%, which would allow you to carry 175lbs with the Draw-Tite receiver. I recommend using a Roadmaster Quiet Hitch for 1-1/4" Trailer Hitches # RM-061-125 to remove the rattle in the adapter to the receiver...
    view full answer...
  • Recommended Trailer Wiring Harness for 2019 Buick Regal TourX
    Based on my research your 2019 Buick Regal TourX doesn't come from the factory with a pre-installed trailer wiring connecter but one can be easily added. For this I recommend the Curt T-One Wiring Harness # C56389. This custom harness simply gets plugged into existing ports behind the driver and passenger side tail lights. After running the hot lead up to the battery you will have a fully functional 4-Way connector to connect with and power a trailer's basic signal lights. I have attached...
    view full answer...
  • What is Towing Capacity of 2018 Buick Regal TourX
    Looks like your 2018 Buick Regal TourX has a towing capacity of 1,000 lbs so you'd need either a smaller trailer or a larger tow vehicle to tow your trailer that weighs 1,600 lbs. The Draw Tite hitch part # 36661 that you referenced is a confirmed fit though and would be a great hitch to use. It's a Class II with more capacity than your vehicle so it would easily handle up to 1,000 lbs. For trailer wiring the kit you'd want is the Curt part # C56389 which is easy to install and very reliable. For...
    view full answer...
  • Trailer Hitch and Wiring Recommendation for 2018 Buick Regal TourX
    For your 2018 Buick Regal TourX I'd recommend the Curt hitch part # C12173 over the Draw Tite # 36661 although both are really great options with a similar design. The reason I recommend the Curt is that in general we see the best quality control from their hitches and it seems the powdercoat is a little stronger which prevents flaking and corrosion. Then for trailer wiring you will need the Curt T-Connector part # C56389 as it installs the easiest and is a great harness. Then for a...
    view full answer...
  • How to Transport Power Chair on 2018 Cadillac XTS That Has Only 100-lb Allowable Tongue Weight
    I checked the online edition of the owner's manual for the 2018 Cadillac XTS and it does indeed state the maximum trailer weight is 1000-lbs, just as you mentioned, but is also notes that the tongue weight of the connected trailer should not exceed 10% of that maximum, which would then be 100-lbs. This note appears on the right-hand side of page 233. The three 1-1/4-inch Class II hitches offered for the car, such as Curt # C12115 shown on the linked page, all have the same rated maximum...
    view full answer...
  • Are Separate 12V Power Feeds Needed for Curt 4-Pole Harness and Autowbrake Trailer Brake Controller
    You can install both the Curt 4-pole wiring harness # C56389 and the Autowbrake Trailer Mount Electric Brake Controller # 3430001 (and the required 7-way kit # ETBC7L) in your 2019 Buick Regal TourX but each one of these items must have its own dedicated power connection to the vehicle battery. I realize its no fun crawling under the car to route those power wires but this is critical for safety and for proper operation of these devices. For a worst-case example, if there were a fault...
    view full answer...
  • Recommended Trailer Hitch Receiver Compatible with 2019 Buick Regal Sportback AWD
    The Curt Trailer Hitch Receiver # C12173 is only a fit for 2018 - 2020 Buick Regal TourX. For your 2019 Buick Regal Sportback, all the versions will use the Curt Trailer Hitch Receiver # C12185. So, that is the hitch receiver I recommend for your Sportback AWD. If you will be towing with this hitch, I recommend the Curt T-Connector Vehicle Wiring Harness # C56389, ball mount # C45521, hitch ball # A-82, and pin and clip # F-4.
    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 Jacob T
Video Edited:
Jacob T
Employee Cole B
Installed by:
Cole B
Employee Wilson B
Updated by:
Wilson B
Employee Kristina F
Updated by:
Kristina F
Employee Isabelle B
Updated by:
Isabelle B
Employee Ronnie R
Written by:
Ronnie R
Employee Conner L
Test Fit:
Conner L

At etrailer we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.