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  1. Custom Fit Vehicle Wiring
  2. Ford
  3. Bronco
  4. 2021
  5. Tekonsha
FITS 2021 Ford Bronco
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

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

Item # TK99VR
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Custom Fit Vehicle Wiring
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2021 Ford Bronco

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2021 Ford Bronco - T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

  • Trailer Hitch Wiring
  • 4 Flat
  • Tekonsha

Quickly and easily install a 4-way trailer connector on your Ford Bronco with this custom wiring harness. T-One connector plugs directly into existing wiring. Powered ModuLite reduces strain on wiring system.


  • 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 ModuLite 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 of 16-gauge bonded wire
  • Comes with dust cap for 4-way flat connector


  • Maximum amperage:
    • Stop/turn lights: 5 amps per circuit
    • Tail lights: 7.5 amps per circuit
  • 1-Year limited warranty


This custom-fit T-One connector plugs into your vehicle's wiring harness, which is located behind the driver's-side and passenger's-side tail lights. You will have to remove the protective covers next to each tail light 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 and insert the provided fuse.

Once installation is complete, the 4-way flat connector will be stowed beneath your vehicle, near the trailer hitch. A mounting bracket (sold separately) is recommended to keep the connector secure.

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.

ModuLite Powered Tail Light Converter

A ModuLite power module is built into this T-One connector. 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 your trailer. This power module functions as a tail light converter to combine 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.

With a ModuLite, your trailer's lights will be powered without overloading your vehicle's electrical system. Because the module draws power directly from your car's battery and bypasses the electrical routes that are used by a basic wiring harness, there is virtually no draw on your tail light circuits.

118849 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite

Installation Details TK99VR Installation instructions

Customer Reviews

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - TK99VR

Average Customer Rating:  5.0 out of 5 stars   (2 Customer Reviews)

Quickly and easily install a 4-way trailer connector on your vehicle with this custom wiring harness. T-One connector plugs directly into existing wiring. Powered ModuLite reduces strain on wiring system.

- TK99VR
2021 Ford Bronco

Fast shipping, won't know until after I get my Bronco and do the install.

- TK99VR

- TK99VR


Ask the Experts about this Tekonsha Custom Fit Vehicle Wiring

  • Troubleshooting Turn Signal Issues with T-One Wiring Installed on a 2021 Ford Bronco
    Since the trailer is working with other vehicles it does sound like the T-One # TK99VR wiring is the issue on your 2021 Ford Bronco. If you use a circuit tester on the 4-Way you can double check and make sure that the 4-Way is working correctly. I would try the connector as well as the wiring before and after the module to ensure that your Bronco is sending the correct signals through. If your Bronco is sending everything correctly (like it should be) then I would think that the wiring...
    view full answer...
  • What 4-Way and 7-Way Connector do You Recommend for My 2021 Ford Bronco?
    From the sound of your question, it sounds like you are wanting an option for both a 4-way and a 7-way to install into your 2021 Ford Bronco and do not currently have any wiring. For a plug-in 4-way harness, I recommend the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # TK99VR. However, you need a separate wiring harness in addition to the # TK99VR to have the 7-way installed. For that part, that is the Universal Installation Kit for Trailer Brake Controller - 7-Way RV...
    view full answer...
  • 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. However, the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector item # TK99VR you were asking about is designed to work with both style of tail lights. Tekonsha is by far the most reliable source for wiring harnesses in the towing business. This has the same style of...
    view full answer...
  • How to Add 7-Way Wiring on a 2021 Ford Bronco
    To add a 7-Way to your 2021 Ford Bronco you will need a 4-Way kit like the recommended T-One # TK99VR and then the Universal Wiring Kit # ETBC7. The T-One plugs in behind the tail lights of your Bronco and gives you the standard light functions while the ETBC7 comes with everything you need for a fully functional 7-Way. Usually we only see 7-Ways with OEM connections for trucks so your anything smaller than a truck you usually have to install a 4-Way and then an additional kit like...
    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...
  • 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...
  • What Hitch and Wiring Harness is Required to Tow a Light Utility Trailer with My 2021 Ford Bronco?
    For a hitch for your 2021 Ford Bronco, I recommend the Draw-Tite Hitch - 2" # DT37GR. The Curt hitch is compatible with all Bronco models and comes with all mounting hardware required for a bolt-on installation. As far as weight capacity, the hitch has a 675 pound maximum tongue weight and a 4,500 pound gross towing rating. In order to confirm whether your vehicle can accommodate this much weight, I recommend confirming your vehicle's weight capacity with you owner's manual. In addition...
    view full answer...
  • Recommended Trailer Hitch Receiver for 2021 Ford Bronco for Spare Tire Clearance
    In order to get the clearance you need for your bike rack on your 2021 Ford Bronco I recommend the Draw-Tite Max-Frame Trailer Hitch Receiver # DT37GR. This Class III hitch has a 2" receiver and bolts onto your rear bumper beam. It has a maximum gross trailer weight of 4,500 lbs and tongue weight of 675 lbs. Make sure to consult your owner's manual so you know what your vehicle is capable of. More than likely the hitch capacity will exceed your vehicle's capacity. Since you will be...
    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 Mike S
Written by:
Mike S
Employee Noah M
Updated by:
Noah M

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