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

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

Item # 118390
Our Price: $59.07
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Custom Fit Vehicle Wiring

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T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector Custom Fit 118390
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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 118390 or order online at 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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Tekonsha Custom Fit Vehicle Wiring - 118390

  • Custom Fit
  • Trailer Hitch Wiring
  • 4 Flat
  • Powered Converter
  • 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 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: 2.1 amps per circuit
    • Tail lights: 4.2 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 tail light assemblies to access this harness.

T-One Connection Location Points Behind 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 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.

118390 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite

Installation Details 118390 Installation instructions

This Product Fits The Following Vehicles

California residents: click here

Customer Satisfaction Score:

Customer Reviews

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 118390

Average Customer Rating:  4.8 out of 5 stars   (94 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.


Well first was the hitch assy. Then wire harness kit for my dodge durango. Assy. Went well. Great product and great service. Thank you


Easy to install. Works the way it shoul d.


Great product, easy to install with idiot-proof instructions. It took about an hour for me to install this but that was only because I'm picky about a nice job. I could have easily been done in 30mins.

Highly recommend!

2006 Dodge Durango

Purchased for my 1956 International I am currently working on it have not finished it yet but have put it on 2006 Durango frame but sure it will work well

2007 Dodge Durango

Wired up a dodge durango for a trailer. The t-one vehicle harness was perfect. An easy way to do the job. The harness came with everthing needed, directions were ok, and the job was completed in 30 min.



So far so good still working after a year.

2008 Dodge Durango

Easy install with the online video at etrailer. I followed the video exactly and it took about 1 hour to install. Item feels solid and almost looks like a factory install.

Dodge Durango

I've been using this wiring harness for a full year now without problems. Installation was easy; just snapping together connectors. No real tools required. The only hiccup was that I needed to loosen one nut so that I could ground one of the new harness' ground wires to the frame of my Durango. If your instructions don't mention a frame ground, then that's something you should try if your wiring harness doesn't work properly at first.


Great product. Shipping was very fast. Installation was very simple the install video was a great help. Customer service was best I have ever seen. Will definitely be ordering again for all my towing needs.

William S.


After a year of use I have to say Im very impressed with this wiring harness. I use it regularly and it has never given any trouble. Great product. Would recommend any day, its worth every penny.

2008 Dodge Durango

I had already had a accessory trailer light kit on my 08 Dodge Durango before ordering this product so it wasn't anything new to me, but I did like how fast and easy it was to install. I backed my Durango into my garage and ten minutes later I was already pulling it out and hooking up to the camper to go camping. Simple easy install, I would recommend this product to anyone I know.


i have only just installed this product so i can't comment on its operations. I can say ordering and shipping was very good with good package tracking. As far as installation this product is a must as far as ease. My only issue would be there is a white wire coming off the control box that isn't addressed by the instructions that came with it nor in any video tutorials available by etrailer. I made the assumtion it was a ground wire given it had an eye connector on the end and the only thing left in the package was a self tapping screw. Hope I'm right. Other than that great company and very easy to install.


Excellent plug in wiring.My vehicle didn't come with the factory wiring harness so I started with this kit. It was a very simple installation if you are at all familiar with vehicle wiring. All the parts were included. Connecting to the factory tail lights was very simple as no splicing was needed at all. A big relief. This kit also includes an isolator which keeps trailer shorts from damaging expensive vehicle electronics. I added the 4-7 wire adapter to this kit to be able to use a trailer brake controller in my vehicle. Excellent service from etrailer.

2006 Dodge Durango

Super great product easy to hook up and great company fast shipping.

2006 Dodge Durango

easy to install, except for the eyeful of dirt from the bottom of my Durango, which of course is no fault of this product! The only thing I noticed is there was no mention in the instructions about the white ground wire and the included screw for attaching that wire to the vehicle. Immediately after the install I hooked up my trailer and took it to town, all the lights worked like they should.

2005 Dodge Durango

This product worked great! I liked the way it fit with my existing wiring.


Installation is very easy - only challenge was properly routing the 12v wire from battery to the rear of the vehicle. Not difficult, just time consuming and requires some thought to be sure it is not close to hot components, has enough slack to account for suspension travel, and is wire-tied often enough so it won't get snagged on brush when offroading. Instructions are well written.


Good product for the moneyExcellent option for those who want a 7-wire connector but are unable to find one. Dealer wanted $180 for this part. This adapter combined with the T-connector harness saved me over $100.
Note: Requires separate ground (white wire). Does not use the ground from the 4-flat wiring harness it taps into. This is detailed in the instructions.

2006 Dodge Durango

Easy installation, Works great. It is a perfect match for my 2006 Dodge

Marc M.


This product still works great

2006 Dodge Durango

Product worked exactly as promised. Installation was simple mostly plug and play although you do have to run a power feed from the battery but simple to do just takes a little time to get a clean installation. Lisa D. Was fantastic. Extremely knowledgeable friendly and helpful. My installation was a little odd so she took time to evaluate several options to get me the best solution. Overall I am very pleased with trailer and will use the for my future needs.

Dodge Durango

easy installation, video of installation was quite helpful. only dirty part of installation was going under the Durango to run the power lead. (having ramps made this easy--plus got a view to see if any part of the frame was rusting) I would recommend this product.

2004 Dodge Durango

The plug in components were easy to use. The power supply was easy to splice. The wiring under the truck was hard to get through the frame, but found a way to send to the fuse box. The system works well and have used it several times already. Might look for a mount for the plug.

2009 Dodge Durango

Great product worked great. Easy instructions to follow. Only thing it didn't have instructions on hooking up white ground wire behind tailight. I figured it out though. Great price I will get all my parts I need in the future from you. Thanks.

2005 Dodge Durango

This has served me very well for over a year now. Easy installation on the Dodge Durango, no problems. We have used it without any issues at all. no problems whatsoever. Very pleased!

2009 Dodge Durango

Just finally got around to installing this kit ... after almost 12 months. Went in relatively easy. It had everything needed and no trips to HW store required.

Only reason for 4 stars is I have not had time to see if it lasts. But so far very good.

2007 Dodge Durango

2007 Durango, product was exactly like advertised price was excellent. Installation video was for a 2007 dodge Durango, most other companies give you a general installation video. Having a video of the exact vehicle makes installing very easy . Total time for this install without a lift was about 2hrs.


2nd Time Doing Business WithI have purchased a tow package and wiring harness from etrailer and they have been great to deal with. I really appreciate the tutorial vidoes.

Show More Reviews

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

  • Troubleshooting 2006 Dodge Durango Wiring Issue While Using Harness # 118390
    I have two ideas to help with wiring on your 2006 Dodge Durango. My first idea is the most likely and it is normally pretty easy to find and fix. Idea#1:If your issue is happening ONLY when the trailer is connected then most likely you have a grounding issue.You will want to make sure that the trailer connector is clean and corrosion free. From there move on to checking the grounds on the trailer. Trailer lights usually ground through the mounting studs. The main ground from the connector...
    view full answer...
  • Wiring Differences Between a 2008 and 2007 Chrysler Aspen for T-One Harness Part # 118390
    There should not be any difference in the wiring process between a 2007 and 2008 Chrysler Aspen. They use the exact same wiring harness so there should not be any differences. All the connectors will be in the same location and should be able to run the power wire to the battery in the same location.
    view full answer...
  • Wiring Harness for a 2006 Dodge Durango
    The available wiring harness for your vehicle, item # 118390 connects inline with plugs behind the taillights and you will need to run a hot lead to the battery. The power wire is needed to protect the vehicles sensitive circuitry. The trailer lights will be powered by the vehicle battery but will get the signals from the vehicle turn, brake and tail light functions.
    view full answer...
  • Why is a Battery Connection Required for Trailer Wiring Harnesses on a 2009 Chrysler Aspen
    Powered trailer wiring harnesses like # 118390 have a direct connection to the battery for 2 reasons. First, it powers the trailer lights instead of drawing the power and the signals all through the vehicle tail light wiring. This helps protect the vehicle wiring. And second it offers additional circuit protection beyond what a non-powered converter can. Basically, you want as much isolation between the vehicle sensitive wiring and electronics and the trailer wiring. The last thing you...
    view full answer...
  • Troubleshooting a Tow Ready T-One Harness on a 2007 Dodge Durango
    It sounds like there is a ground issue on the trailer. If you can I would try connecting your trailer to a different tow vehicle that you know works correctly to verify that the problem is in the trailer or the tow vehicle. The reason I think it is a ground problem on the trailer is because you said that when you switch on your headlights the trailer lights quit working altogether. That is usually a dead giveaway for a ground problem. What usually happens is that the lights will work to...
    view full answer...
  • No Voltage on Running Light Circuit of 7-Way Trailer Connector on 2007 Dodge Durango
    It sounds like you've successfully eliminated the trailer wiring as being the cause of the problem. Since you've tested the trailer connector on the vehicle, and found everything but the running light circuit working correctly, I believe you have a blown fuse. According to the online copy of your owners manual, the fuse for the 'Trailer Tow Park Lamps' is in the Integrated Power Module box in the engine compartment next to the driver's side fender. There's two black boxes with removable...
    view full answer...
  • Does Tekonsha Trailer Wiring Kit for 2006 Dodge Durango Draw Amperage When Parked
    Even though the T-One Vehicle Wiring Harness # 118390 is connected to the vehicle battery when installed it won't draw any amperage unless you apply the brake lights, turn signals, or running lights of your tow vehicle and there is a trailer connected. So if you parked your vehicle it would not drain the battery with or without a trailer connected. It would be similar to how your vehicle battery is connected to your vehicle's wiring but it doesn't draw amperage unless you activate a circuit...
    view full answer...
  • Trailer Lights Not Working with T1 Trailer Wiring Harness on a 2005 Dodge Durango
    The first thing you will want to check on the T1 harness # 118390 for the 2005 Dodge Durango is the power wire connection. If this harness is not connected to the positive terminal of the vehicle battery then it will not function. Also, the fuse that comes with it must be in place. You can also check to see if the fuse is intact. Next, move on to testing the wires that go into the converter box from the vehicle. The red power wire should have at least 12 volts. The green and yellow wires...
    view full answer...
  • Trailer Wiring Harness for a 2005 Dodge Durango
    If your 2005 Dodge Durango came with the factory installed 7-Way and for whatever reason it is no longer there then yes, using # 118381 will provide the lighting functions for the trailer: running lights, brake lights, and turn signals. If the vehicle did not come with a factory trailer connector then you would use harness # 118390 which plugs in line with the vehicle tail light wiring and requires a direct connection to the vehicle battery. I have linked some videos and instructions for you.
    view full answer...
  • Tow Ready Custom Wiring Harness Recommendation for a 2006 Dodge Durango
    The problem you are experiencing is because you have tail lights on your 2006 Dodge Durango and the brake lights are on a separate circuit from the turn signals. You will need a converter box so that you can convert that signal so that your trailer with combined tail lights can be used with your vehicle. What I recommend you get is a Tow Ready Custom Fit Vehicle Wiring Harness # 118390 for your Durango. This harness will plug in-line with your tail lights and has the necessary converter...
    view full answer...
  • Trailer Wiring Tail Light Converter for a 2005 Dodge Durango
    The Tow Ready wiring harness # 118390 plugs in line with the vehicle tail light wiring and then runs to a converter box that takes the signals used by the vehicle and converts them to the signals used by the trailer. Trailers have combined turn and brake lights some vehicles do and some do not. Others are a little less cut and dry. What this harness does is take the more complex signals used by the vehicle and translates them to work with the simple functions on the trailer. This harness...
    view full answer...
  • Where to Attach Ground Connection for 118390 Trailer Taillight Converter on 2007 Dodge Durango
    Tekonsha recently upgraded the # 118390 Taillight Converter with an improved ground connection for more reliable operation. The white wire is a ground connection, and you'd use a self tapping screw to attach the ring terminal to the vehicle body behind the taillight assembly next to the converter box as shown in the provided photo.
    view full answer...
    Image 1 for
  • Wiring Harness Malfunctioning on a 2008 Dodge Durango
    My first inclination is that the tail light connectors were flipped on your T-One Harness, part # 118390. The side that has the yellow and red wires should be connected to the driver side, and the green wire connector should run to the passenger side. The problems you described above usually are caused by this having the connectors flipped. If this is not the case, please write back and we will have to do some diagnosing. I have included a link to the instructions for reference.
    view full answer...
  • Trailer Wiring Harness for a 2005 Dodge Durango SLT 4.7L without Factory Tow Package
    It does not sound like your 2005 Dodge Durango has a factory tow package if you cannot find the plugs for the harness. But to be sure you can always have a Dodge dealer run the VIN through their system to see how the vehicle is equipped. Without the factory tow package you would use wiring harness # 118390. I have included a link to the installation instructions for you to view and a video showing a typical installation. This harness does connect in line with the tail light wiring. You...
    view full answer...
  • Trailer Wiring Harness for a 2007 Dodge Durango without Factory Tow Package
    Curt trailer wiring harness # C55381 will only fit your 2007 Dodge Durango if it came with the factory tow package. If you cannot find that factory connector anywhere then it is likely that your model does not have the factory tow package and you will need a different harness. For a model without the factory tow package I recommend Tow Ready wiring harness # 118390. I have included a link to a video showing how it installs as well as a link to the installation instructions for you.
    view full answer...
  • Replacement Trailer Wiring Harness Recommendation for 2008 Chrysler Aspen
    Sounds like you have a shorted out trailer taillight converter. Any time we see one of the pins of a connector show voltage all of the time that indicates that box has shorted out most likely due to a short on the trailers wiring. Curt harnesses like the one you have part # C55597 are notoriously easier to short out than other brands. So what I would recommend you do is find and fix any short on your trailer's wiring and then install a # 118390 in place of it and you'll be good to go.
    view full answer...
  • Recommended Trailer Hitch Receiver for 2005 Dodge Durango
    The Hidden Hitch brand has been discontinued because it was the same hitch as Draw-Tite with just a different sticker for years. Draw-Tite made both hitches as they bought out Hidden Hitch many years ago. For the same hitch as 87562, you will want the Draw-Tite Max-Frame Trailer Hitch Receiver # 75162. If you will be towing with this hitch, I also recommend the ball mount kit # 989900. It comes with 2 ball mounts; one with a 3/4 inch rise or 2 inch drop and one with a...
    view full answer...
  • Why Do Some Trailer Wiring Kits for 2005 Dodge Durango Require Running Battery Wire
    The Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # HM42245 does have the advantage of having a much easier install than other options since it does not require running the power wire up to the vehicle battery but the battery wire offers your vehicle protection from trailer wiring shorts from transferring to the vehicle wiring. This is because the power draws from the battery and not the vehicle taillights. So a short would not hurt anything. So your...
    view full answer...
  • Brake Controller Install Kit and Hitch Recommendation for 2005 Dodge Durango
    For trailer wiring you would need to first start with the 4-way part # 118390 that will plug inline with the vehicle taillight connectors like you mentioned. To convert the 4-way to a 7-way will require the part # ETBC7 that comes with everything needed to make the conversion and install the brake controller. I attached an install video an instructions for you to check out as well. For a hitch the Curt part # 13072 would be a great option as well.
    view full answer...
  • T-One Vehicle Wiring Harness on a 2007 Chrysler Aspen No Longer Working
    I would recommend you start by using a circuit tester like # PTW2993 and test the pins on your trailer connector while each function is activated. If you find that you are not getting a signal on the turn signal/ brake light circuits, use the tester to test the wires going into the converter box. If you have signal going into the box, but not exiting, the converter is bad and must be replaced. Before replacing the T-1 Harness, you'll want to carefully examine the wiring on your trailer....
    view full answer...
  • Parts Needed to Install a 7-Way and Trailer Brake Controller on a 2006 Dodge Durango
    To add a trailer brake controller to a 2006 Dodge Durango without the factory tow package you will need several parts. First you will need to install trailer wiring harness # 118390. I have included a link to a video and a link to the instructions showing how to install this harness. After you install the 4-Way you will then need to install # ETBC7 which will provide the 7-Way and the wiring needed to install a brake controller. I have included a couple of links that will walk you through...
    view full answer...
  • Trailer Wiring Kit Needed for 2006 Dodge Durango Without Factory Hitch or Wiring
    If your 2006 Dodge Durango didn't come with trailer wiring from the factory then you'll need the T-One Wiring Kit # 118390. This gives you 4-Way wiring for your basic trailer lighting functions. I've attached an installation video of this kit that you can check out. To complete a towing setup you also need a ball mount kit. I recommend checking out Ball Mount Kit # 989900 because it includes two ball mounts, one with a 3/4” rise/2” drop and the other with a 2-3/4” rise/4” drop, a 1-7/8”...
    view full answer...
  • Installation, Drilling and Trimming Required to Install a Trailer Hitch on a 2008 Chrysler Aspen
    What our installers do when installing hitches on the Aspen, like your 2008, is to first get the hitch in position and attach the u-bolts that go over the vehicle bumper structure. Then, they use the hitch as a template and drill through the bumper structure from the back of the vehicle. Then they drill out the other side. The bumper structure is hallow so you do not have to drill all the way through. It is easier to get the holes lined up correctly this way. Take a look at the instructions...
    view full answer...
  • Trailer Hitch Receiver Fit for 2005 Dodge Durango Limited
    We do have a trailer hitch receiver that fits a 2005 Dodge Durango Limited, but it is different than the model you referred to. I checked with Curt and can confirm that the correct hitch for your '05 Durango Limited is the Curt Trailer Hitch Receiver # 13297. This is a complete bolt-on installation and I have added a link to the instructions for you to check out. If you are looking to tow with your Durango and do not have the factory tow package wiring harness I recommend adding the T-One...
    view full answer...

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