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  1. Custom Fit Vehicle Wiring
  2. Tekonsha
  3. 4 Flat
  4. Trailer Hitch Wiring
  5. No Tow Package
  6. Vehicle End Connector
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
Tekonsha

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

Part Number: TK77FR
In Stock
$110.52
Retail:$130.38
You Save: $19.86
Custom Fit Vehicle Wiring

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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. 1-800-940-8924 to order Tekonsha custom fit vehicle wiring part number TK77FR or order online at etrailer.com. Free expert support on all Tekonsha products. Great prices and Fastest Shipping for T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector. Custom Fit Vehicle Wiring reviews from real customers.
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  • Reviews (46)
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Tekonsha Custom Fit Vehicle Wiring - TK77FR

Highlights

  • Custom-fit, plug and play: Easily install without cutting or splicing vehicle wires.
  • 16-gauge bonded wire: Provides a durable and reliable connection for your trailer's lights.
  • ModuLite power module: Prevents vehicle electrical overload by drawing power directly from battery.
  • Compatible with adapters: Works seamlessly with 5-pole, 6-pole, and 7-pole adapters (sold separately).
  • Protective dust cap included: Keeps the 4-way flat connector clean and corrosion-free.
  • Tail light circuit capacity: Supports up to 7.5 amps per circuit ensuring strong signal lighting.

Features to know about

Effortless Installation: Plug-and-Play Connectivity

Gone are the days of cutting, splicing, and taping wires. With the T-One Vehicle Wiring Harness, you can forget about complicated wiring processes. This harness is designed as a plug-and-play solution, making it easy to connect to your vehicle's existing wiring system. It fits seamlessly into various BMW X3 models, including 2020 and 2021 versions, ensuring you spend more time towing and less time troubleshooting.

Power Without Overload: ModuLite Power Module

Worrying about electrical overload is a thing of the past. The built-in ModuLite power module draws power directly from your vehicle's battery, bypassing the delicate circuits of your tail lights. This feature ensures your trailer's lights are powered without straining the vehicle's electrical system, providing a safe and reliable connection every time you hit the road.

Works Across Models: Custom Fit Design

This custom-fit design ensures that it fits a range of BMW X3 models, from the standard to the M-series. Even for 2022 models, where tail light configurations have changed, this harness can be adapted. It’s an efficient solution for anyone with an X3 model, providing reliable and consistent performance without the need for additional modifications.

Stay Clean and Protected: Dust Cap for 4-Way Flat Connector

When not in use, this wiring harness includes a practical dust cap to protect the 4-way flat connector. This prevents dirt and moisture from infiltrating and causing corrosion. It's a simple yet effective feature that extends the life of your connectors and ensures they remain functional every time you need them.

Reduce Installation Hassle: Direct Connection to Battery

For those who value a neat and tidy installation, this wiring harness allows you to run a dedicated hot lead directly to your car battery. Accompanied by a fuse holder and fuse, it minimizes the risk of electrical faults or poor connections, resulting in a clean, professional-looking install every time.

Robust Construction: Durable 16-Gauge Bonded Wire

Featuring solid, weatherproof, one-piece construction with 16-gauge bonded wires, this harness is built to withstand the elements. It’s designed to provide long-lasting durability and consistent performance, giving you peace of mind during all your towing adventures.

Specs

Electrical Specs

  • Maximum amperage:
    • Stop/turn lights: 5 amps per circuit
    • Tail lights: 7.5 amps per circuit

Warranty

  • 1-Year limited warranty

118823 Tekonsha T-1 T-Connector - 4 Wire - Modu-Lite Converter Included

Installation Details TK77FR Installation instructions

This Product Fits The Following Vehicles



California residents: click here


Customer Satisfaction Score:

Ratings & Reviews

4.8

46 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.

by:

Pretty standard plug-n-play harness. The power wire was a bit of a pain, though, in the X3 as you have to be really careful with your routing. The instructions and video make it look like you can just flop the power wire over the battery and be done with it. In reality, to make it look at least halfway near decent, you have to get creative - AND be careful if you ever plan to use the tuck away for the cargo cover.
Still, better than having to route it from the back all the way to under the hood.

Robert profile picture

Robert

11/14/2024

After a year, I stand by the above review. Harness is working great. Still have to be careful around the power wire broke it once. Is this my own fault? Possibly. Should the instructions have been clearer and a better routing path been identified? Probably. Will I fix this in the future? Also probably.



by:
BMW X3

I bought this for a 2021 X3 xDrive 30e, which is the PHEV version of the X3. The rear compartment, where the batteries are, looks much different than the standard X3. You must by much more careful with this vehicle as it has a 48V system mixed in, and the space where you run the green wire across to the passenger side is much different. I had to be creative to avoid many components that are not present on the standard ICE X3. In all, it worked great, and I was able to securely mount the module by the left taillight assembly, and store the harness in the cargo cover stowage when not in use.



by:
2020 BMW X3

I connected the wiring harness in 20 minutes and it works great. I do not usually work on cars, installation was simple, this product does not require splices.



by:

straigh forward install. Works as adve rtised.



by:
BMW X3

Installed this on my 2021 BMW X3. Quite easy and stress free to install when following the tutorial video. No installation step was skipped in the tutorial. I was not lacking any parts to complete the project. A few days after installation I hooked it up to a U-Haul trailer and it worked as expected and proceeded without issue on my road trip. When not being used the cable tucks away unseen.



by:

This wiring harness was not confirmed to fit my 2023 BMW x3 but the connectors looked right and they were . Had to move the brown wire on the left connector and on the right side the green wire had to move to align with the green wire on the car.



by:
2019 BMW X3

Installed this on a 2019 BMW X3 M40i. Very easy if you follow the video by etrailer on how to install this wiring harness. Make sure you have a good crimping tool.



by:
2021 BMW X3

The wiring harness was really easy to use. Installation took less than 30 minutes.



by:
2020 BMW X3

Super easy install on my BMW X3m. The install video was super helpful.

Ryan profile picture

Ryan

2/15/2024

No longer have the car but the wiring harness worked great the few times I towed with the BMW.



by:
2018 BMW X3

Fantastic product. Easy to install and works great. Perfect fit!



by:
2020 BMW X3

The installation video made this very e asy



by:

We are happy with our whole package including hitch, receiver, wiring and ball mounts.

Rick profile picture

Rick

2/16/2023

Plug and play. I have only used it once since installation, and it did work as advertised.



by:

Easy install and seamless operation



by:
2018 BMW X3

Great video on how to install, complete kit with everything you need.



by:
2018 BMW X3

plug and play with no issues, everything you need in this kit.



by:

super easy install



by:
2019 BMW X3

Worked perfectly plug and play no complaints at all.



by:
BMW X3

Needed pin swaps to work properly on my 2022 X3.



by:
BMW

Works well on a 2020 BMW X3M40i



by:
2018 BMW X3

The video is direct and helpful.



by:

Looks good, hopefully it is plug & Play



by:

Incredible service! Stays with you every step of the way.



by:

Great product. Easy install!



by:



by:
2019 BMW X3


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Show More Reviews

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Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jameson C
Expert Research:
Jameson C
Employee Kathleen M
Installed by:
Kathleen M
Employee Chris R
Video Edited:
Chris R
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Written by:
Alexander C
Employee David F
Test Fit:
David F
Employee Thomas T
Video by:
Thomas T

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