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

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

Item # TK35VR
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Our Price: $165.87
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. 1-833-496-1390 to order Tekonsha custom fit vehicle wiring part number TK35VR or order online at Free expert support on all Tekonsha products. Guaranteed Lowest Price 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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Tekonsha Custom Fit Vehicle Wiring - TK35VR

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

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.


  • 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 in rear cargo area
    • Plug in T-connector
    • Run hot lead to car battery
  • Includes ModuLite power module that 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 in the rear cargo area. You will have to remove the plastic threshold cover and some interior lining 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 in your rear 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.

ModuLite Power Module

A ModuLite power module is built into this T-One connector. 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.

118869 Tekonsha T-1 T-Connector - 4 Wire - Modu-Lite Converter Included

Installation Details TK35VR Installation instructions

This Product Fits The Following Vehicles

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

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Review of Tekonsha Custom Fit Vehicle Wiring - T-One Vehicle Wiring Harness 4-Pole Flat - TK35VR

Hi, everybody, Andy here with, and today we're gonna take a look at this T-One vehicle wiring harness with the four-pole flat trailer connector. Now, this is a custom-fit part that is designed to fit the 2020 and newer Tesla Model 3. To confirm that this is going to work for your vehicle, take advantage of our vehicle fit guide on our website. And input the year, make, and model of your vehicle, and our fit guide will let you know if this will work for your vehicle. Now, this harness provides a four-pole flat trailer connector at the back of your Tesla to power your trailer signal lights. It is compatible with five-pole, six-pole, and seven-pole adapters, and those adapters are sold separately.

And as you can see, an included dust cap for the four-pole flat connector is tethered to the plug housing. So this is going to ensure that you don't misplace it or lose it, and that dust cap is gonna cover up those connection points when you're not using it. So it's gonna keep it clean and free from debris, and it will be nice and clean for when the next time arises that you are going to need this. Now, this black box on the harness is the ModuLite power module, and the ModuLite ensures that your vehicle's wiring matches that of your trailer. It connects directly to your vehicle's battery to avoid overloading your vehicle's electrical system, thereby reducing strain on your Tesla's wiring system.

This harness is designed to connect quickly and easily. So there's no splicing wires, no alteration to your vehicle's wiring, which could lead to damage or voiding warranties. The connection with the yellow wires are gonna go to your driver's side, and the connections with the green wires are gonna go to your passenger side of your Tesla. Now, these custom-fit T-One connector plugs, they're gonna plug into your vehicle's wiring harness, which is located in the rear cargo area. You will have to remove the plastic threshold cover and some interior lining to expose your vehicle's taillight wiring connectors.

So after locating your wiring connector mating T-One connector harness, you want to disconnect the vehicle wiring harness from both the driver and passenger's taillight assemblies, and you want to be careful to not damage any locking tabs. These T-connectors are custom fitted for your Tesla. So they will match up perfectly with the connection points on your vehicle, and they're gonna snap and lock together for a nice, tight, secure fit. So once you have these plugged in, you will need to make a good ground connection. And this ground wire is this white wire, and it has a ring terminal attached to it.

And it does come with a self-tapping screw. So you can get that grounded to a suitable location, such as your Tesla's frame or crossmember. Just make sure that the surface is clean and rust-free. Then you will need to mount your ModuLite box to a safe, out-of-the-way location, and you can do that with another mounting screw if you have one on hand or with this included double-sided adhesive tape or with one of the many cable ties that comes included with your kit. Next, you will want to run the hot lead from the ModuLite box to your vehicle's battery, and that's gonna be this short, black wire that, as I mentioned, is gonna come out of this box. And this short, black wire is going to get connected to one end of this included bundle of black wire using one of the included butt connectors, and then the other end of this bundle is going to get routed to your Tesla's battery. And once you have this routed to the battery, you are going to take this fuse holder, and what you will do is cut the yellow wire of your fuse holder in half and connect one of the wires with the second butt connector to the routed end of this bundle of black wire. And then you will take the other half of this fuse holder wire, and that's going to get, and a ring terminal that is included with your kit. And that's gonna be attached to that other wire, and then this is going to connect to the positive post of your vehicle's battery. It does come with a 15-amp fuse, and that's going to go into the holder. And then this holder has a fuse cap that's going to keep your fuse safe and protected. I mentioned that this comes with cable ties, and so you're gonna have plenty of cable ties to secure any excess or slack in your wiring. And once the installation is complete, you're gonna have a four-way flat connector ready to go, and then you'll just stow this in the rear cargo area when you are not using it. The maximum amperage for the stop/turn lights is gonna be five amps per circuit, and for the taillights it's gonna be 7.5 amps per circuit. And this is constructed of 16-gauge bonded wire, so it's a high-quality wiring harness. Instructions are included to walk you through each step. And it is also recommended that you use a small amount of dielectric grease on all of your electrical connections, like the plugs on the vehicle and the four-pole connector itself. It is designed to help prevent electrical failures caused by corrosion and moisture. And I've included the item number to that dielectric grease on your screen. And you just pop in that item number in the search field on our website, and that will take you to the product. And that would be a strong recommendation to get along with this wiring harness. Well, that's gonna conclude our look today. I do hope that it was helpful for you. Again, my name is Andy. Thank you for joining me..


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Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Andy C
Installed by:
Andy C
Employee Sabrina W
Written by:
Sabrina W

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