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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 # C42WR
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Our Price: $93.50
Custom Fit Vehicle Wiring

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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. 1-833-496-1390 to order CURT custom fit vehicle wiring part number C42WR or order online at Free expert support on all CURT products. Guaranteed Lowest Price 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 (34)
  • Q & A (0)
  • Photos
  • Why etrailer?

CURT Custom Fit Vehicle Wiring - C42WR

  • Custom Fit
  • Trailer Hitch Wiring
  • 4 Flat
  • CURT

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.


  • 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 behind tail lights
    • 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


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


This custom-fit T-connector plugs into your vehicle's wiring harness, which is located behind the driver's-side and passenger's-side tail lights. 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 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.

56468 Curt T-Connector Vehicle Wiring Harness with 4 Pole Trailer Connector

Installation Details C42WR Installation instructions

This Product Fits The Following Vehicles

Customer Reviews

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - C42WR

Average Customer Rating:  4.5 out of 5 stars   (34 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.


The wiring harness I received does not fit my 2022 bronco had to return it and order a new one.

It could be possible you purchased the wrong harnesss. The Curt # C42WR you purchased is for 2022 Ford Bronco models with LED taillights. If you do NOT have LED taillights, youd need part # C87BR
Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
-- Etrailer Expert Mike L - 08/26/2022


I'm a little bummed that Ford didn't provide a more friendly provision for this as a standard item. Thumbs up to Curt for making a best effort in development of a solution. While I would appreciate something a little more finished, I appreciate the ability to configure and finish in an OEM fashion. Thanks Curt, thanks etrailer!


Only works with led taillights.

2021 Ford Bronco

2021 bronco. Great quality but… the passenger taillight plugs had the wiring wrong. I found that the right blinker wasn’t working because of the way they had the pins pushed into the plugs in the wrong location. They had the pin for turn signal in a part of the plug that didn’t go to anything on the vehicle side. The green wire should have been where the white wire with black mark is. I was able to pull the plugs apart and move the pins into the correct locations. CURT NEEDS TO FIX THIS.
And maybe it was only the one I received.

I have reached out to Curt, they mentioned that this harness will only work with LED tail lights. They have passed this issue to their engineering team to research.
-- Etrailer Expert Thomas M - 01/24/2022

2022 Ford Bronco

Exactly as advertised. Simple plug and play. Installed on my 2022 Bronco. I did have to re-work the pins to accommodate the halogen (non LED) tail lights but that was a simple process. Highly recommend this product.


The description of this needs to have a warning for LED tail lamps only. I’m going to change the pins around but this will not work for non LED. There is nothing listed about this that says LED until you get to the reviews. Come on etrailer be better!

When the fitguide is used for a 2021 Ford Bronco and the wiring harness option is ed there is a down menu to choose whether the Bronco has LED tail lights. For those without LED tail lights you would want to use part # 119190KIT.
-- Etrailer Expert Jenny N - 04/06/2022


This wiring harness was a piece of [email protected]! If it wasn’t for the guy on the [onllne] channel “Budget Bronco” I never would of gotten this thing to work. Watch the video!

I recommend watching the video review that we have in the link below.
-- Etrailer Expert Jenny N - 09/20/2022

2021 Ford Bronco

I was fortunate to be one of the ones to order and eventually receive a 2021 Ford Bronco First Edition. Strangely enough, that meant that I was not able to order certain accessories with it one being the Tow Package. I contacted etrailer and explained what I was trying to do (hitch and 7Pin) and they sent me a list of everything I needed to make it work


Fast shipping and easy installation.

2021 Ford Bronco

Nicely done by Curt. I didn't get towing package on my ordered Ford Bronco, so this along with Curt Hitch 13493 will do the job. Plug and play except having to run a wire to the battery for 12v supply. Haven't installed yet.

2022 Ford Bronco

This fit my new bronco perfect fast and easy to install just plug and play

2022 Ford Bronco

Fairly straightforward to install. Instructions were sinple to follow, including providing bolt head size.


Very easy to install and works great


Easy install, worked like a charm

2021 Ford Bronco

This is a great design. I had the whole thing installed in about 45 minutes. Plugs right in to existing connectors and wires tuck away neatly. Would definitely recommend.


Installation was easy


Great product with clear directions. A fairly easy install


It does what its supposed to do.









Show More Reviews

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

  • Does Curt Trailer Wiring Harness for 2021 Ford Bronco Work with LED Taillights
    Yes, the Curt trailer wiring harness part # C42WR is a confirmed fit for your 2021 Ford Bronco with LED taillights. This kit was actually designed for the versions of the vehicle that have LED taillights.
    view full answer...
  • Wire Gauge Used On Curt T-Connector Vehicle Wiring Harness # C42WR
    Per Curt their T-Connector Vehicle Wiring Harness # C42WR uses 14 gauge wire for the harness.
    view full answer...
  • Curt Trailer Wiring Harness that Fits 2021 Ford Bronco
    Curt has a trailer wiring harness that fits your 2021 Ford Bronco with the part # C42WR which is a plug and play style of harness but the part number you mentioned is not the correct kit to use.
    view full answer...
  • Complete Towing Setup For A 2022 Ford Bronco
    Yes, for your 2022 Ford Bronco, you can use the Curt Trailer Hitch Receiver # C76WR. This hitch will bolt to your vehicles frame, has a maximum towing capacity of 3500-lbs, and a maximum tongue weight of 350-lbs. You'll want to check your vehicle owners manual for your vehicles maximum towing capacity, and compare that to the hitches maximum towing capacity, and use the lowest rating between the two. You may also want wiring so your trailer, or hitch mounted accessory has lights while...
    view full answer...
  • Will the Curt Vehicle Wiring Harness Work on 2021 Ford Bronco With LED and Halogen Taillights
    The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # C42WR is designed to fit a 2021 Ford Bronco with LED taillights. This will not work with your LED and Halogen lights. For your 2021 Ford Bronco, I recommend the Tekonsha T-One Vehicle Wiring Harness # TK99VR. We have found Tekonsha to be the most reliable when it comes to a 4-way wiring harness like this. This wiring harness uses the same style t-connector which plugs into your existing wiring for a 4-way...
    view full answer...
  • Best 4-Flat Wiring Harness for a 2021 Ford Bronco Sport
    I have a solution for you that has the same plug n play installation but the part you referenced does not fit your 2021 Ford Bronco Sport. You will want Tekonsha T-One Vehicle Wiring Harness item # TK46FR. This custom-fit T-One connector plugs into your Bronco's wiring harness, which is located in the rear cargo area. I have linked an installation video so you can follow along with the process.
    view full answer...
  • Recommended 7 Pin Connector For A 2021 Ford Bronco
    When it comes to installing a 7 pin connector on your 2021 Ford Bronco with LED Taillights you first will need The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # C42WR. This harness will mirror your trailer's brake, stop, and turn lights with your vehicle's brake, stop, and turn lights. Depending on if your towing a trailer with brakes or a trailer with out brakes is the next piece. If your trailer has brakes you will need The Universal Installation Kit for...
    view full answer...
    Image 1 for
  • Recommended Trailer Hitch Receiver For 2022 Ford Bronco
    I recommend the Curt Trailer Hitch Receiver, # C76WR. This has a maximum gross trailer weight of 3,500 lbs. and a max GTW of 350 lbs. and is a Made in USA product. For a 4-Pole Flat Trailer Connector, I recommend the Curt T-Connector Vehicle Wiring Harness, # C42WR if your Bronco is equipped with LED lights. If not, select the Curt T-Connector Vehicle Wiring Harness, # C87BR. If you need a ball mount kit, we have the etrailer Ball Mount Kit for 2" Hitches, # 989900 that includes everything...
    view full answer...
  • Recommendations For Mounting A 4 And 7 Pin Adapter To 2021 Ford Bronco Factory Hitch
    Factory mounts will end up being different than aftermarket ones, so the only thing I can recommend is removing the 4 Flat mount and drilling two holes in the hitch for the Hopkins Endurance Multi-Tow # HM47180 to mount to. On the factory hitch where your 4 Flat mount is located, it is designed for holding wiring like this, but how the 7 Way will mount will end up being very low as it will hang down below the receiver opening. What may be a better option is the Hopkins 7-Pole and 4-Pole...
    view full answer...
    Image 1 for
  • Wiring Harness that is Compatible w/ a 2021 Bronco w/ LED and Halogen Tail Lights
    I have a solution for you but the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector item # C42WR you referenced isn't designed to work with both the LED and halogen taillights. And neither is the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector item # TK99VR you were asking about. Both custom wiring harnesses only work with LED's. For a wiring harness that works with halogen bulbs you will want the Upgraded Heavy Duty ModuLite Circuit Protected...
    view full answer...
  • Best Trailer Wiring Harness For 2021 Ford Bronco
    Great choice with the hitch for your 2021 Ford Bronco with the Draw-Tite # DT37GR, and the best option between the Curt # C42WR and Tekonsha # TK99VR wiring harnesses that fit is absolutely the Tekonsha: - T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # TK99VR The # TK99VR is the best option because we have found over time that Tekonsha makes the most reliable trailer wiring harnesses in the industry. This harness also has the higher amp ratings between the two that...
    view full answer...

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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 Dustin K
Video by:
Dustin K
Employee Wilson B
Updated by:
Wilson B
Employee Mike S
Written by:
Mike S
Employee Bradley B
Test Fit:
Bradley B

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