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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 # 118500
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118500 - Custom Fit Tekonsha Trailer Hitch 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 - no cutting, splicing or tapping required. Powered ModuLite reduces strain on wiring system. 1-800-496-5010 to order Tekonsha custom fit vehicle wiring part number 118500 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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  • Reviews (51)
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Tekonsha Custom Fit Vehicle Wiring - 118500

  • 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 - no cutting, splicing or tapping required. 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 - no cutting or splicing of wires
    • Locate connection point in rear cargo area
    • Plug in connector
  • 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: 5.6 amps per circuit
  • 1-Year limited warranty


This custom-fit T-One connector plugs into your vehicle's wiring harness, which is located beneath the floor of your rear cargo area. You will need to remove either the spare tire or center storage bin to access the wiring harness. Once you've plugged in the connector, open your fuse box and locate the fuse position indicated in the instructions. Then insert the included 15-amp fuse.

Once installation is complete, the 4-way flat connector will be stowed within the spare tire compartment of your cargo area.

It is recommended that you use a small amount of grease on all electrical connections - the plug 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.

118500 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite

Installation Details 118500 Installation instructions

This Product Fits The Following Vehicles

California residents: click here

Customer Reviews

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 118500

Average Customer Rating:  4.9 out of 5 stars   (51 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 - no cutting, splicing or tapping required. Powered ModuLite reduces strain on wiring system.


Integrated with my factory wire harness with no issue. Works great. Good quality.


Super easy . etrailer video showed location of my car harness connector 15 minutes and I was done . Great


I purchased this to go with my new trailer hitch. The installation was exceedingly simple as it only involved removing a bit of trim from the trunk area and attaching the box to the factory wiring harness. The only thing I don't like about it the fuse is very close to the harness which means you have to disassemble the same trim to replace a blown fuse.


Fast and easy installation... saved $ by ordering here.

Works great, plug and play.
Troy B - 09/24/2021

2009 Acura RDX

Besides having the best selection of parts and accessories for trailers and the like, their pricing is most likely the lowest you will find. From the point of ordering online to the final destination, my front porch, tracking of the package is always available!

2010 Acura RDX

If the installation of a wiring harness could be any easier, I can't imagine how. I installed this harness on our 2010 RDX, and things went pretty much like clockwork. I made more work for myself than necessary by removing some of the trim pieces on the driver's side. I really just needed to remove the two barbed trim fasteners for the rear sill plate and the two on the passenger-side. Then with the spare tire removed, I was able to partially lift the molded styrofoam block on the passenger side to see the blue-taped trailer connector pigtail. I just cut the blue tape with a pocket knife, and pulled the pigtail out far enough to connect to the new harness; then slipped the connection back under the styrofoam block. Then it was just a matter of peeling the plastic off of the double-stick tape on the control module (black box) and affixing it to the "forward" wall of the spare tire bay. At least on a 2010 RDX, this is truly a 15-20 minute jog.

Finally, I tip my cap to The ordering process was flawless, the delivery was lightning fast (23 hours), the directions were clear, and the video library was very helpful. Salute!

2011 Acura RDX

This is the second trailer wiring kit I've had to buy for my 2011 RDX. The wiring kit fits perfectly. The connector is right where the directions say it is, and all of the connectors work. However, my first one lasted through 2 U-Haul rentals, then stopped working outside of warranty. I don't know why it failed - the fuse is good and none of the wires were frayed. I'll install this new kit and see how long it lasts.

2007 Acura RDX

The wiring harness was very easy to install, only taking about 10 minutes. The instructions were great and after watching the video, I had confidence that I could do it. Thank you, etrailer.

2012 Honda Accord

I had been researching the best product to fit my needs and this one was it. I selected this product because of the protection the module would provide to my cars electrical system. When I received the product and read the instructions and saw how easy this would be I immediately started and I was done in fifteen minutes. And that was because I wanted to do a custom install for the location of the plug for the trailer. So far so good. I tested it with my trailer and all lights, turn signal and stop lights functioned perfectly. Thank you for making this so easy!!!


First off let me say etrailer is Official! So I purchased a tow hitch 1st it came....... Then a week later I purchased a ball mount, ball, and tow light kit and was upgraded to 3-5 day shipping and received it in 3 days and they made sure I was updated along the way! Couldn't be more Impressed!!! Thank You etrailer you have a customer for life, I will tell anyone I know that is looking for trailer accessories.

Dallas, TX

2007 Acura RDX

Received the wiring harness on time and installed it in my 2007 Acura RDX with no problem with the click of a connector, couldn't be easier. Checked out the connection with a led tester and all worked as planned. The real story will be tomorrow morning when I hook it up to tow my popup camper home from the dealer.

2015 Honda Crosstour

Installed in 2010 Crosstour in about 15 minutes. Easy to do. Directions could be a little better but still easy. Just need to remove the small bin in luggage area on drivers side. Just one bolt to remove (easy to replace). Fuse goes in the “trailer” socket in fuse box. It doesn’t sit down as far as the other fuses, but it seats in the socket fine.


This wiring harness was very easy to install. Took me a total of 8-min. to do the complete install. Go to the [online] to look up the make and model of your vehicle. Highly recommend this product.

2011 Acura RDX

Plug and Go! The site made is very easy for me to locate the exact wiring match for my vehicle (2011 Acura RDX). It arrived faster than I expected, the directions were very clear and easy. I plugged in, hooked up my trailer and hit the road with all lights operating properly.

2010 Honda Accord

Product is similar to my previous installed harness except there was no identification of wiring as on my old harness. Also the picture of the fuse location is of no use.


The wiring harness is easy to install, just plug and go.

2011 Acura RDX

The harness Itself is an excellent product. It was a perfect fit for my 2011 RDX. Could not have been easier to connect.

However detailed instruction on how to remove the styrofoam and trim moldings would have been extremely helpful. The included instructions advise to anchor the harness using the double stick tape on a flat surface beneath the styrofoam trim. No guidance on how to get the styrofoamfoam out of the way.

2010 Honda Accord

Installed on my 2010 Honda Accord Crosstour. This was so so easy, I could not believe it !! Simple Simple Simple !!! One plug to plug in.. Click & it is in stalled ...
The ONLY item t o mention, is the 15amp fuse works- but does not fit all the way down even with the other oem 15amp fuses. The Honda oem fuses are slightly different & fit down INSIDE the holders. The 15amp fuse supplies with this unit plugs into the stabs ok, but will not fit down inside like the others.. I dont think I matters...

2008 Acura RDX

Pops right in, just reach under the foam block to the right of the spare tire. Grommets are available to send the wires through the body, but you'll have to splice the wires back into each other.

2012 Honda Crosstour

I have never bought anything that came with video instructions an a well planned photocard on how to use and install a product installed it myself in about 40 minutes I took my time. Works as expected and would recommend this product to others. Plug and play trailer wiring for later model honda.

2012 Honda Crosstour

The instructions were very easy to follow and the trailer hitch fit perfectly. Thanks for providing a great product.

2012 Honda Crosstour

The instructions were very easy to follow and the trailer hitch fit perfectly. Thanks for providing a great product.

2012 Acura RDX

This was purchased for a 2012 Acura RDX and was exactly what I needed. The instructions were simple and thanks to the existing connector in the RDX, you literally just plug and play. I have plugged it into my external lights and all combinations of lights work. It has not been on a long trip yet but that is coming up in a couple of weeks.


I am very happy with your product, all components arrived as ordered, installation was straightforward, after one year of use, not a single problem.

2007 Acura RDX

Installation of this wiring harness took longer than I expected, but only because I didn't read the instructions carefully. If you follow the instruction sheet, it shouldn't take more than 10 minutes to install this. After installation, everything worked perfectly the first time.

Show More Reviews

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

  • Trailer Lights Not Working on a 2007 Acura RDX with Wiring Harness # 118500 Installed
    First make sure that both the in line fuse (red) and the mini fuse (blue) are both installed. Otherwise the harness will not work. I know that the instructions say to install the fuse for the Honda Crosstour but it is also possible that it is needed on your RDX. Check the fuse location and determine if the fuse is missing or needs to be replaced. Also, make sure that the adapter you are using is grounded to the vehicle frame in a location that is bare metal. If cannot be grounded to a...
    view full answer...
  • Location of Trailer Wiring Harness Plug on 2007 Acura RDX
    The Tow Ready # 118500 fits both the 2007-2012 Accord Crosstour and the 2007-2012 Acura RDX. You'll want to make sure you're looking at the portion of the instructions that relate to the RDX, not the Crosstour. The connector for the Tow Ready # 118500 is located in the spare tire compartment below the floor of the cargo area. To access it, you'll need to remove the cargo area floor and the spare tire. The connector will be locate to the right of where the spare tire sits, as shown in the...
    view full answer...
    Image 1 for
  • Installation Instructions for Tow Ready Trailer Wiring Harness # 118500 on a 2011 Acura RDX
    Installation of Tow Ready Wiring Harness, # 118500, is fairly straight forward. Below I have outlined the instructions for you. First, open rear hatch. Temporarily remove all floor coverings, exposing the spare tire compartment. Remove the spare tire. Next, locate blue 6 pin tow plug near the foam cargo tray. It will be taped to the vehicle electrical harness with blue tape. Then, you will insert the T-Connector harness into the vehicle Tow-Plug harness and lock it into place. Locate a...
    view full answer...
  • Is Fuse Installation Required for Both Tow Ready Harnesses # 118500 and # 118569 in Acura RDX
    Yes, both of the Tow Ready trailer wiring harnesses you referenced, parts # 118500 and # 118569, require you to install the supplied fuse in the vehicle's fuse box located in the engine compartment. Please note that these two harnesses are a fit for different model year ranges of the Acura RDX. The # 118569 fits 2013 and 2014 model years while the # 118500 fits 2007 through 2012 vehicles. I have linked an installation video for your reference.
    view full answer...
  • Installing A Trailer Wiring Haness In A 2011 Acura RDX
    For your 2011 Acura RDX, the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 56008 may require an extra fuse to be added, but it does not require a dealer. You can see in the attached video of the 2015 model where that fuse is located under the hood of your vehicle in the fuse box. It was not needed in the 2009 model. The Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118500 may also require this fuse and it is included with the...
    view full answer...
  • Trailer Hitch and Wiring Recommendation for 2010 Acura RDX
    For your 2010 Acura RDX the Draw Tite hitch part # 75784 is a confirmed fit and will work well for towing a small trailer or carrying a bike rack. I like this option over the Curt as it does not require the use of a stabilizer strap like the Curt does when carrying a non-supported load like a bike rack. I attached an install video for this for you to check out as well. For trailer wiring you'd then want to use the Tekonsha kit part # 118500 which will give you a 4-way. This brand of trailer...
    view full answer...
  • Installing Trailer Wiring on a 2013 Honda Accord Crosstour
    The harness on the 2013 Honda Crosstour is not easy to get to and may be forward or backward on the harness it is supposed to be taped to. But if you have taken all those panels out, like in the video I have linked, and are absolutely certain that it is not there then you would need a different harness. For a T-connector harness for your 2013 Crosstour use # C56215.
    view full answer...
  • Curt or Tekonsha Wiring Harness for 2008 Acura RDX for Trailer Hitch
    First, you made a good choice with the hitch for your 2008 Acura RDX with the Draw-Tite Trailer Hitch Receiver # 75563. And I also recommend going with the Curt T-Connector Vehicle Wiring Harness # 56008. The reason we like this one over the T-One Vehicle Wiring Harness # 118500 you mentioned is because the Curt has a higher maximum amperage rating, which means this harness will give you the best prevention against potential shorts.
    view full answer...
  • Where is Fuse for Trailer Wiring Harness Used on 2008 Acura RDX Installed
    The Tekonsha # 118569 trailer wiring harness you'd looked at isn't a fit for a 2008 Acura RDX, it fits the 2013-2018 model. For your 2008, you'd use either the Curt # 56008 or the Tekonsha # 118500. The 10A fuse included with the Tekonsha # 118500 or the Curt # 56008 installs in the inline fuse holder of the connector that plugs into the vehicle. The additional fuse included with the Tekonsha # 118500 isn't needed for the RDX installation, it's used if you're installing the harness on...
    view full answer...
  • Does the EcoHitch Hidden Trailer Hitch Receiver fit a 2012 and 2014 Honda Crosstour?
    The EcoHitch Hidden Trailer Hitch Receiver item # 306-X7299 you referenced fits both the 2012 and 2014 Honda Crosstour's. If you are needing a wiring harness for your 2012 Honda Crosstour I recommend the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector item # 118500. Their wiring harnesses are the best in the business and most reliable. This harness plugs into existing wiring in your rear cargo area and does not require any cutting or splicing of wires. It provides...
    view full answer...
  • Does Rear Fascia Need to be Bent to Install Draw-Tite Class III 75784 Hitch on 2010 Acura RDX
    I spoke with my contact at Draw-Tite regarding the install of the # 75784 Class III receiver on your 2010 Acura RDX. Unfortunately, they doesn't have any specific information about which particular model years the fascia would need to be temporarily moved. If you look at the installation instructions, you'll see that it's a pretty simple and straight forward installation. On some vehicles, there's not enough room to swing the hitch up into place, so the brackets holding the fascia need...
    view full answer...
  • Parts Needed to Tow Utility Trailer with 2010 Acura RDX
    We have just what you need, but there is not a Class II hitch for your 2010 Acura RDX; instead there are Class III hitches with 2" receivers that are rated higher than a Class II, so they're well suited for your needs. I recommend using the Draw-Tite Max-Frame Trailer Hitch Receiver - Custom Fit - Class III - 2" # 75784 which installs without any drilling required and will have a little bit better ground clearance than the Curt # C13154 that is also a confirmed fit for your RDX. For the...
    view full answer...
  • Class III Hitch for a 2012 Honda Crosstour
    Yes, the EcoHitch Hidden Trailer Hitch Receiver - Custom Fit - 2" item # 306-X7299 is a class III hitch. It is confirmed to fit your 2012 Honda Crosstour. This hitch is custom fit and bolts to your Honda with included hardware. If you need a wiring harness to control your trailer or lighting functions I recommend the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector item # 118500. This custom-fit T-One connector plugs into your vehicle's wiring harness, which is...
    view full answer...
  • Trailer Hitch Recommendation for a 2012 Honda Accord Crosstour
    On all of the trailer hitches for the 2012 Honda Accord Crosstour, the cross member is going to be visible below the rear fascia. That does include the Curt hitch # 11002 as you can see in the picture I have provided. What I recommend is Draw-Tite hitch, # 24852, which is great if you will be using the hitch with an accessory like a bike rack or cargo carrier but can also be used for towing if your vehicle is rated for it. The recommended ball mount is # 3590 and you can use 1-7/8 inch...
    view full answer...
    Image 1 for
  • Recommended Trailer Hitch To Use Saris Freedom 2 Bike Rack on 2014 Acura RDX 2014
    The Draw-Tite Class III trailer hitch you mentioned, part # 75784 would be a good choice, but the Curt Class III, # C13130 is the most affordably priced hitch option we offer for your 2014 Acura RDX. The Curt hitch has a slightly higher capacity (which would be limited by the vehicle's towing capacity if it's less than that of the hitch.) The Saris Freedom 2 bike rack you already have, which I'm guessing is part # SA4412B would indeed be compatible with the hitch. Your rack will have plenty...
    view full answer...
  • Parts Needed to Equip 2010 Acura RDX to Tow Trailer with Electric Drum Brakes
    I can help you select the components needed to equip your 2010 Acura RDX to tow a small trailer with electric brakes. For a 2-inch hitch I suggest the no-drill installation Draw-Tite # 75784 which offers a 4000-lb towing capacity (check your RDX owner's manual for the car's rating). If you have no trailer wiring connector now you can use 4-pole kit # 118500 along with our brake controller install kit # ETBC7. These two parts include all components needed to have a functional 7-way trailer...
    view full answer...
  • Trailer Hitch and Wiring Recommendation for a 2007 Acura RDX Towing an Aluminum Boat
    I would recommend a Class III hitch, like the Curt Class III Receiver Hitch, item # 13536, for your 2007 Acura RDX. Class III hitches offer the greatest range of accessories and options for towing and carrying items at the rear of your vehicle. You will also need wiring to activate the tail light system on your boat trailer. The T-One Vehicle Wiring Harness with Upgraded Circuit Protected Modulite, item # 118500, is the correct wiring harness for your vehicle and provides protection for...
    view full answer...
  • Trailer Hitch Recommendation for a 2012 Honda Accord Crosstour
    I do have 1 trailer hitch that is listed as a fit for your 2012 Honda Accord Crosstour. Take a look at the Draw-Tite Trailer Hitch # 24852. Draw-Tite does list this hitch as fitting the 2012 models. If you plan on doing some towing, the correct ball mount is # 3590 and you can use pin and clip # PC2. For a ball, use # 19256 (1-7/8 inch diameter) or # 19258 (2 inch diameter). For trailer wiring use the T-One Vehicle Wiring Harness, # 118500. I have included a link to the installation instructions...
    view full answer...
  • How Difficult is the Curt C13154 Class III Hitch Installation on 2011 Acura RDX
    The Curt # C13154 Class III hitch install on a 2011 Acura RDX is pretty straightforward. One a difficulty scale of 1-10 with 1 being very simple and 10 being very difficult, we rated this install as a 4. We estimate a trained technician would take about 40 minutes to complete the install, or roughly double that for the typical do-it-yourselfer. The only tools you'll need is a metric socket set and a torque wrench. If you'll be using the hitch for towing purposes, you'll also need a trailer...
    view full answer...
  • Recommended Trailer Hitch for a 2008 Acura RDX
    For your 2008 Acura RDX, the two 2" hitch receivers you mentioned, # 13536 and # 75563, have the different tongue weight and towing weight ratings. The # 13536 has a 300-lb tongue weight and 3500-lb towing weight, while the # 75563 has a 400-lb tongue weight and 4000-lb towing weight. They both have a similar design and mount. One distinguishable difference is that the Curt hitch is made in the USA and the Draw-Tite hitch is made in Mexico. Also, Curt requires the use of a stabilization...
    view full answer...

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Info for this part was:

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