Install a 4-way trailer connector on your vehicle without cutting or splicing into your wiring. Zero-contact interface sensors identify the current flowing through each wire by simply clamping onto it. Circuit-protected module is made using SMT.
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This revolutionary wiring method makes it fast, easy, and safe to add a 4-way connector to your vehicle so you can power your trailer's lights. Unlike traditional tail light wiring harnesses, which either splice into your vehicle's wiring or plug into designated ports in your factory harness, this system bypasses your vehicle's wiring entirely. Just clamp the intuitive sensors onto the individual wires of your OEM tail light harness and let the ZCI system do the rest.
Zero-Contact Interface Sensors
Each zero-contact interface (ZCI) sensor included with this harness is able to read the current that travels through the wire it is clamped onto. Upon sensing the specific modulation of that wire, a signal can be sent along the wire that connects the sensor to the included 4-way flat trailer connector. That signal is then transmitted through the connector to activate the appropriate function on your trailer lights.
Universal, Worry-Free Design
No Splicing, Cutting, or Connecting to Factory Wiring
Because the ZCI sensors can read the signals sent through your vehicle's wires just by clamping onto them, no cutting or splicing is necessary. The system completely bypasses all of your vehicle's wiring. As a result, your trailer's lights will be powered without overloading your vehicle's electrical system. And there is no chance of damaging feedback either.
When using this ZCI harness, you don't have to worry about voiding your warranty, nor do you need to be concerned about any potentially damaging errors on your part if you're not an experienced do-it-yourselfer. And if you have a vehicle that doesn't allow certain modifications - like a leased car or truck - you can install this harness and remove it later with no obvious alteration to the vehicle.
Maximum Compatibility
This wiring harness is universal. You can use it on any vehicle that operates on a 12V, negative ground system. Because installation is so simple, you can easily remove the unit and transfer it to another car or truck at any time.
In addition, the ZCI sensors are able to read the signals sent by multiplex wiring systems and systems with pulse width modulation (PWM) and low-side-switched wiring, making the harness compatible with nearly all automotive wiring systems. This unit also works with both standard incandescent tail light bulbs and LED bulbs.
Built-In Tail Light Converter
Most trailers run on a 2-wire system - wherein the brake and turn signals are carried on a single wire. Many vehicles, however, are built with separate brake and turn signals. This type of system is referred to as a 3-wire system. If your vehicle operates on a 3-wire system, it will need to be converted so that it will be compatible with the wiring system of your trailer. This is done by adding a tail light converter to your wiring setup to combine the brake and turn signal functions of your automobile so that they run on a single wire to properly activate your trailer's tail lights.
This ZCI unit has a tail light converter built in to ensure proper functioning with any vehicle that operates on a 3-wire system. If your car has a 2-wire system and therefore does not need a converter, don't worry. The method of installing the sensors will take into account the wiring configuration of your vehicle so that only the necessary sensors are used, making sure the appropriate signals are sent back to the 4-way.
Installation
This universal harness connects to your vehicle's tail light wiring harness. To connect, just follow the included instructions. There are 4 ZCI sensors included. Each sensor has a colored label on it. Depending on your application, you will need to connect all or some of these sensors to the factory wires indicated in the instructions.
To get the power necessary to operate, the harness must be connected to a 12V power source. The included installation kit provides the hot lead required to connect this module to your car battery. When all connections have been made, connect the hot lead to the black wire on the ZCI power module and run the other end of the lead up to your car battery. Connect the hot lead to the included fuse holder, and then connect the fuse holder to the positive terminal on your battery. Then insert the included 15-amp fuse into the fuse holder.
Once installation is complete, the 4-way connector will be stowed in an out-of-the-way location either within your cargo area or beneath your vehicle, near the trailer hitch. If you choose to mount the connector near your hitch, a mounting bracket (sold separately) is recommended to keep the connector secure.
It is also recommended that you use a small amount of grease on all electrical connections on the 4-pole connector to help prevent corrosion.
Surface Mount Technology
Each ZCI wiring harness is built 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? SMT components 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.
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Average Customer Rating: 4.7 out of 5 stars (352 Customer Reviews)
Install a 4-way trailer connector on your vehicle without cutting or splicing into your wiring. Zero-contact interface sensors identify the current flowing through each wire by simply clamping onto it. Circuit-protected module is made using SMT.
The product works well for the most part. The only issue is that it doesn't trigger the brake lights on my Kendon motorcycle trailer.
Katrina B - 05/03/2022I love my hitch, but the installation of this harness for my Audi Q5 was a huge disappointment. I think it's absurd that the wiring has to hang out of the hatch. I ended up buying something different from the installer that could store UNDER THE BUMPER where it should be. Since the box was misplaced, I was unable to return it. I'll maybe try to sell --- or just throw it away. It was an expensive mistake.
I used it on a 2017 Chevy bolt (think Chevy discurages people from installing a trailer hitch) since it did not come with any trailer hook up instructions. I think it gave my instaler a work out since he never did one before, but despite the cost I think it was the right way to go instead off cutting into wires etc. I dont use a trailer that much, but it has worked absolutely fine. Only problem has been that I think installer disturbed a wire hook up to a parking light (that is only needed-if lift gate is open) so he has not gotten around fixing that since he has to get into the trunk inards to do it.
Super easy to install on my 2013 MINI Cooper Coupe, no cutting or wire splicing needed. The MINI tailights incorporate both LEDs and regular incandescent bulbs and have a somewhat convoluted wiring harness, but I had no issues and everything worked as it should out of the box. Recommended.
Installed on a 2018 Audi Q5. Installation was not easy, partially due to working with the panels on the Audi, partially due to the module being hard to configure properly. After 20+ hours working on it, I got it to a point where it correctly recognizes 'most' signals. For whatever reason, the left turn signal does not work, regardless of how many times I adjust the connections and reset the module. It was a cheap solution that gets me 80% of the way there. I'll also note that there is little/no online reference material available, beyond the installation videos that etrailer posted; this makes troubleshooting nearly impossible.
Jenny N - 01/04/2022Great wiring harness, does NOT require and cutting what so ever. Sal FROM customer service is very helpful. I would recommend for a friend to help to make the install go faster. Over all great, dealer said I would need a special computer program for the Harness to work properly, that is incorrect. Just follow the instructions that are included and you will not regret your investment. Car 2018 Audi Q5
The trailer hitch and wiring assembly have worked flawlessly. After calling several local installation outfits and receiving estimates of $2,000+ I decided to install myself. I have a little mechanical experience but this was the first hitch and wiring harness for me. This is my wife's X5 so I was a little nervous about popping rivets and pulling the rear bumper cover off, but eTrailer has excellent step by step video instructions by model year. The order included replacement rivets and detailed instructions. They could not have made this any easier. I really took my time and completed the job in about 5 hours. The final install looks professional and clean. The no-splice wiring harness is amazing - worth every penny. Tools: I was able to easily pop off the existing plastics rivets, and installed the new rivets (included from eTrailer) with pliers pretty easily - you may want to borrow a plastic rivet gun from your local hardware or auto parts store. On the X5 your have to cut a small notch out of the underside of the bumper cover. I happen to have a Dremmel which worked well. You may be able to use a razor blade. The plastic is not that thick. Pictures are attached. Thanks etrailer!
2012 VW GTI (autobahn edition) Installation (DSG) I had some small issues and hiccups along the way, so in order help out since I couldn't seem to find vehicle specific help, here is what I did. I did buy the CURT 4-way flat connector tester (Item #126) first to make my life easier when testing. It helps. Buy it. First - start by removing the cargo floor carpet and pulling down the drivers side wall carpet. I did find it necessary to take the moulding trim off the top portion of where the hatch cover locks in, along with the rear seat belt guide trim so I could run the wires to the battery cleanly. There is a few star bolts holding the trim alongside the rear seats when folded down, so just do a search if can’t find it (one cover has to be popped off) Second - Wiring. This was a little bit of a guess, as I have 3 wires, and my meter didn’t seem to be helpful since they were so small and close together. Here’s what works (drivers side): - “Stop” module clips over the black/red wire - Middle brown wire isn’t used - “Left” turn signal module clips over the green/black wire - Passenger side right turn signal clips over the green/black wire - I screwed the ground right into a side structure panel Running the battery cable was the bigger time suck. - Stated above I had the drivers side rear panel trim and carpet removed, and I continued removing the front/rear drivers floor sill trim. I ran the black wire along the current loom and tucked it under the floor carpet. - I then ran it behind the hood latch and towards the top of the metal foot rest, keeping it behind the carpet - This is where you get to the firewall. There is a piece of foam. Remove it. Now you’ll see a rubber grommet where the clutch pedal would go through if you have a standard. I took that out, drilled a small hole to run the wire through that I attached the wire to a metal hanger to fish up and to the right of the battery box. Fish it up, grab it, and pull it through. - Slide the grommet back into place (your wire would have been already through it) and snap it on. - Make your connection to the battery and follow initiation instructions.
This kit works perfectly! A reasonably straightforward installation, though not for a DYI'er who is uncomfortable ripping into the trim and lighting wiring harness of their vehicle. A reasonably accurate wiring diagram is very helpful, but not necessary because trial and error works well with Hall sensors used in this kit (i.e. no cutting and splicing wire is required). Once installed, the trailer lighting load is easily handled by the power module without feedback to the vehicle lighting control circuit, although my setup does not interface with a trailer brake controller so I cannot judge full performance. One hint - do not loose the heavy stock reference card that reminds one of the programming routine, While performing other electrical work on my car needing battery disconnection, I can never remember the programming sequence for the trailer lighting controller. Not to worry, though, the product support site has the info.
Works, could not get lights to work 100% correct but close enough to use the trailer. Brake lights are on when running lights, and 4way hazard lights don’t work. But turn signals work and brakes dim the trailer lights so good enough. Audi A3 etron
The Tekonsha wiring harness was a bit difficult to install, as the clip-on connections are a somewhat bulky to fit in my Tesla Model 3's tight spaces. The good news is: they work as promised like a charm with our tiny camp trailer's lights. In truth, I have only had to use them once, but cannot imagine that any unforeseen problems would occur with them in the future.
Installed on 2018 Jeep Grand Cherokee Limited with no tow package. Install was kind of a P.I.T.A. But worth doing on your own to avoid the stealership. Not too much electrical knowhow required, as the black wire on Jeep tail lights are all ground. Running the power cable was the most difficult part, and required removing the interior rear quarter panel, which I managed to break a plastic clip. Would not recommend this on a Jeep, as there is no simple way to install this on the interior of the vehicle since the tail lights are wired 100% outside of the car. I’d say skip if you are looking into this for a Jeep, and wait for an OEM trailer harness to come out from mopar.
I installed the kit on a 2016 Audi A6. I could not find any videos for this car but did watch the video on the Audi A4 which was helpful. Audis are not easy to get information on and are sometimes difficult to work on. The A4 info was very helpful in accessing the wiring but from there it was trial and error in which wire to use for each function. The sensor is very easy to install although on the A6 it is very cramped to work on. IT TOOK ME CONSIDERABLE LONGER TO DO THE INSTALLITION THAN ESTIMATED. This was not due to the kit but to wire identification and some problems with the wiring on my trailer I hAVE NO PROBLEM WITH THE QUALITY AND OPERATION OF THE KIT. For accomplishing the job I rate it 5 stars. I first saw this kit a couple months ago and though it quite expensive (at that time $xxx +) At the time I ordered it the price was just over $xxx. The Audi is a very high tech car so I decided to pay this to avoid the possible trouble a direct wiring job could incur. The product was shipped promptly but before I received it the price had dropped to $xxx. This does not make me feel good about the value of my purchase. I like your web site and the easy of using it. Sorry I have no photos.
Sierra K - 10/05/2021Installed on my 2017 Corvette Z06. Easy install and works great. Suggested by one of there tech’s to not void the warranty. No wires get cut or pierced. Thanks for a great product.
David1 H - 04/24/2021Wiring to the battery on my model 3 would have been a pain so I just put a small battery in the back with the module. It is really nice being able to haul a small trailer.
I had the harness installed. It is easy enough to do yourself providing you have the tools and mechanical experience. The harness works great and can be removed should I want to use it on another vehicle.
Combine this kit with a couple of YouTube videos (Thank you U-haul), the installation isn't difficult. Do purchase a circuit tester with an attachment that wraps around a wire and pierces the insulation. The cheap circuit tester that comes with the kit is worthless.
David W - 10/27/2021Excellent product. Trailer wiring works flawlessly with no “wire touch” to the Porsche OEM wiring.
The wiring system works remarkably well. I was skeptical of a system that only parallels the original wiring harness instead of a hard connection but it works great and saved me from having to cut in to my cars wiring. I highly recommend this system. The installation video is a bit lacking in a few details but most handy people should be able to figure out the routing through the car body without great difficulty.
We own an Audi Q5 and we had the unit professionally install at our local garage. I am disappointed in the way the unit performed. We used it to pull a small uhaul trailer, and the lights worked only spardically. The tail lights worked most of the time, but the signal lights seemed to only work at random. For this emergency trip it was adequate, but I would not reccomend this product.
Brooke M - 08/25/2021I am very satisfied with the ZCI wiring harness. However I do not appreciate the amount of emails you are sending me. Remove my email from your promotional advertising. Thank you.
This is an excellent kit - bought it for my '17 Chevy Bolt, and installation went without any problems. Just make sure you do things accurately and to best quality. The kit's only as good as your installation.
I installed this on a 2019 VW Alltrack. Well designed, works great! Instead of running a power wire to the module per the instructions, I just power it from the 12v connection in the rear of the car as needed.
Works better than expected. No "learning required by device. Works fine when powered up, even though i normally remove power between trailer uses to eliminate load.
Better t - 10/07/2021My son installed the hitch and the wiring. Hitch was installed and wiring took about 3 hrs. He’s a auto technician and he was amazed seeing a wiring without slicing. Great product.
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