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Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. Connector plugs directly into existing wiring. Powered converter reduces strain on wiring system and is made using SMT to ensure superior performance.
Features:
Specs:
Installation
This custom-fit T-connector plugs into your vehicle's wiring harness, which is located behind the interior trim panel in your rear cargo area. Once you've plugged in the converter, insert the included 10-amp fuse into the integrated fuse holder.
Once installation is complete, the 4-way connector will be stowed in an out-of-the-way location within your cargo area. Adhere the black converter box to the frame of the car using the double-sided tape provided. Secure any loose parts of the T-connector with the provided cable ties.
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.
A tail light converter is built into this T-connector. This converter is a circuit-protected, battery-powered unit that bypasses the electrical routes that are used by a basic wiring harness. As a result, there is virtually no draw on your tail light circuits.
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 the trailer. This converter combines 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.
Curt builds each tail light converter using surface-mount technology (SMT). This method of construction involves soldering electronic components directly to the surface of a printed circuit board. SMT eliminates the need for leads, which are used in older through-hole technology. The result is a circuit board that is smaller yet provides more routing area and that offers superior performance, reliability and durability.
Circuit boards constructed using SMT have been shown to perform better under rough conditions with excessive vibration than those made using the through-hole method. And where would vibration be more likely to occur than in towing applications? Curt converters also produce less heat, leading to increased durability and longer life. In addition, lower levels of resistance ensure better performance, especially for parts that operate at higher frequencies.
Each Curt circuit board is made using high-quality components that are pieced together in the most technologically savvy fashion, leading to greater predictability and reliability in functioning.
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Fast, simple install.
GREAT
Very Good easy to install
Easy to install
Works and installs as advertised.
Fast delivery did not install yet looks very well made
Very simple to install. Just watch the video.
It installed exactly as advertised and works great.
Easy to install, and came with all the instruction Shipped fast!
Fast shipping, good price, easy installation. Very satisfied!
Good product. Video online of installation was most impressive part. Written instructions were not great.
Great helpful website, great prices and fast shipping makes your company a pleasure to work with.
Easy, easy, easy installation. Directions are clear, no wire cutting or splicing required, no guesswork or wire color sorting- just plug it in. Plenty of wire ties are provided for routing the wires however you like and keeping it neat.
Wow really plug and play the dealer could not get a wiring harness and I put this in in 5 Minutes. The instructions are super clear and easy to follow.
this kit snapped right into the factory plug, then i scratched a good ground and drilled in a self tapping screw. It all works well. A nice piece of double coated tape would have been helpful behind the box but was not provided.
The Curt 56040 wiring harness was a cinch to install. Don't know if we're going to use it in the future as we just planning on "towing' our bicycles. But it's ready to go if we ever attach a trailer.
Easy to install. If you watch the video on the outback, it shows you to have to remove the entire driver rear panels, but have someone with small hands reach up and grab the plug for you, and it will save you some time.
Easy to install, just follow directions. Cut off ground connector, install provided larger connector and just install under frame bolt right next to factory harness. Honestly took longer to remove all the pieces to install than actually plugging unit up and being ready to go.
This was the best internet shopping experience I have ever had. I talked with an extremely knowledgeable representative when ordering, was given FREE SHIPPING, a tracking number that was also tracked by a representative, was sent 4 follow up emails, it arrived exactly when they said it would arrive which was exceptional during the Holiday season. I am 100 % satisfied with the service and my “Made in the USA” product.
The wiring was incredibly easy to install. I did end up crimping on the slightly larger end for grounding on a nearby bolt for the Subaru Forester it went in. It was really just plug it in, take the fuse out of the bag and put it inside, undo a nearby bolt for ground place the ground wire around the bolt then put it back and and I was done. The harness that plugs into the trailer has a rubber cover as well which is nice.
I bought this wiring harness for my 2024 Subaru Ascent. This harness was easy to install even though it didn’t come with instructions. The length of the wire connecting to the 4-way plug was the correct length with about 8 inches to spare and plugged right into the connector on the vehicle. I would recommend this product.
Came as fast as lightning, the instructions for a 2018 Subaru forester were incorrect, the plug assembly is tied up on the drivers side aft most side wall panel, pictures added, not on floor as shown in the instructions and on etrailers video, took a bit of hunting to find it, but after that it took more time to clean up.
Carter453
5/26/2025
Works as advertised!
Excellent quality, fit perfectly in place. Little nervous about dismantling the rear my new Outback (and my wife was more nervous still), but the video was very clear and complete. Only oddity was the bolts I took out to remove the bumper frame had 17mm head and the bolts supplied to replace them needed 11/16” wrench. Still, all parts needed were there, and the fish wires (I only needed one) were phenomenal, making what would have been the most frustrating part of the job almost comically simple.
I appreciate that you've clearly thought through everything you can provide to make installation easy and successful.
Connector is correct, but directions are way off. Needs to be updated. The OEM plug is not in the same place as previous body styles. I chose not to close the wiring in with the trunk because that’s a dumb idea. There’s a supplied hole with a grommet right next to the OEM plug. Makes it easy to pass wires through and be right on top of the hitch. And there’s a fantastic spot for body ground, that doesn’t require running a self tap screw into the car. Will attach pictures.
I have had and installed my products from etrailer and never had a bad experience. All the hitches and wiring have been great without any problems. Delivery has been quick and right on time. Products have been packaged well with quality control. installation video make installation easy. The only problem I have had was when my son in law was having a problem with his trailer and decided to test it by plugging into one of my vehicles and blew the electronic module, not the products fault just a diagnostic IQ problem.
Anthony
8/23/2025
I have installed e-trailercurt on multiple autos and it has been awesome. No problems, well thought out engineering. I have had e-trailercurt set up on two vehicles for over a year now without any problems.
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Dan F.
11/27/2025
I haven’t had any issues with the wiring harness, I’ve pulled many trailers and the connection to trailer lights are tight.