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  1. Custom Fit Vehicle Wiring
  2. Mazda
  3. CX-5
  4. 2016
  5. CURT
FITS 2016 Mazda CX-5
Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

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

Item # C56310
Our Price: $58.24
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Custom Fit Vehicle Wiring
Confirmed to Fit
2016 Mazda CX-5

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CURT custom fit vehicle wiring for your 2016 Mazda CX-5 are available from Installation instructions and reviews for your Mazda custom fit vehicle wiring. Expert service, and great custom fit vehicle wiring prices. carries a complete line of CURT products. Order your Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector part number C56310 online at or call 1-800-940-8924 for expert service.
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  • Reviews (62)
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2016 Mazda CX-5 - Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

  • Custom Fit
  • Trailer Hitch Wiring
  • 4 Flat
  • Powered Converter
  • CURT

Quickly and easily install a 4-way trailer connector on your Mazda CX-5 with this custom harness. T-connector plugs directly into existing wiring. Powered converter reduces strain on wiring system and is made using SMT to ensure superior performance.


  • 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 a tail light converter 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 using surface-mount technology (SMT) for consistent, reliable performance
    • Maximizes trailer light yield and intensity while producing minimal heat
    • Ensures superior operation in rough road conditions
  • Comes with dust cap for 4-way flat connector


  • Maximum amperage:
    • Stop/turn lights: 3 amps per circuit
    • Tail lights: 6 amps per circuit
  • Limited 1-year warranty


This custom-fit T-connector plugs into your vehicle's wiring harness, which is located in your rear cargo area. You will have to remove the trunk floor coverings and the rear and side scuff panels 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.

Once installation is complete, the 4-way connector will be stowed in an out-of-the-way location within your 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.

Powered Tail Light Converter with Surface-Mount Technology

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.

Curt SMT Circuit Boards

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.

56310 Curt T-Connector Mazda CX-5 Wiring Harness with 4 Pole Trailer Connector

Installation Details C56310 Installation instructions

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - C56310

Average Customer Rating:  4.8 out of 5 stars   (62 Customer Reviews)

Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring. Powered converter reduces strain on wiring system and is made using SMT to ensure superior performance.


This is a replacement for my previous Curt harness / adapter, which developed an intermittent fault in the running lights after several years of use. After troubleshooting I concluded the fault was interior to the module, which is sealed and not possible or practical to repair--so I replaced it.


I've had this on my Mazda CX-5 for the past year, I've used it numerous times, hauling one dirtbike on a hitch carrier, hauling multiple large motorcycles on a Kendon Motorcycle Trailer, and also using my No-Mar tire changer on it as well. It's been super durable and problem free. Hoping for many more years of quality use out of it.


I bought the C56310 trailer hitch and the recommended wiring harness for my 2016 Maxda CX 5. I jacked the back of my car up and installed it in my garage. Everything went together smoothly with no issues. Between the hitch and wiring it took under two hours. My local trailer place wanted almost $600 for the hitch wiring and installation. I spent $**. Excellent support videos and online support. Quality product.

I use my hitch weekly for towing my boat. I have had zero issues. Everything was easy to install and works perfectly. I have not seen a factory installed hitch on a Mazda CX-5 so when others see it they ask me where I got it and I always recommend ETRAILER.
Bill. M - 07/20/2017

2012 Chevrolet Volt

It was very simple and straightforward to install. It took about 20 minutes to do. Fortunately there was a 12 volt outlet in the rear of the car to hook the power feed up to it


Great product. Etrailer has wonderful customer service and I love the video review/demonstrations a lot of their products have as well.


I purchased the wiring harness along with a 2" hitch, as well as a Hollywood Racks bike rack. The videos for all three items made the installations easy. I purchased the hitch shortly after purchasing a Mazda CX-5, primarily for use with a bike rack. I went ahead and purchased/installed the harness at the same time so that if and when I need it for towing, I'm ready to go. This harness, slaving off the battery for power directly, versus the lights, made sense - brighter, no concerns of blowing fuses, etc.

On a side note, I really like my Hollywood Racks bike rack - it holds bike snug, it's secure, it's easy to mount, and best of all, I can switch from a two bike mount to 4 bikes in maybe 5 minutes.

I haven’t actually used the wiring harness as of it, so nothings changed as far as my review goes. That said, we moved to Germany later last year, and trailer lighting requirements including bike racks that reduce visibility of rear tail lights and license plate require lights and plates be attached to those extensions. Bike racks available here now only come with lights and room to attach a plate, but the hitches are different. SO, I will be purchasing some trail tail lights and a harness soon and building a basic light and license plate board that I’ll hang attach to the bike rack I also purchased. I’ll be sure to seek help as necessary, and intend to purchase from etrailer. Will be in touch.
Eric - 06/11/2018


This is a true plug and play adapter for your trailer lights. It takes more time to remove the panels than it does to install the adapter. It works with my 2016.5 CX-5 that has partial LED lighting. Power is available in the rear from the 12V power outlet that is always hot and has a 15A fuse. There is a body ground behind the left tail light, just perfectly placed. Below and behind the left tail light is a flat spot and a natural place to put the control box. DON'T use it; the trim panel will not fit with the box there. Tuck the control box behind a flange just to the rear of that perfect place for the box.

Not much to say after a year. It works great! Has not caused any problems with the tail lights or car. Perfect as can be.
John - 08/28/2018


After gathering my tools up and setting my timer it took me 90 minutes to get this job all buttoned up. The instructions were clearly written with good pictures. I would add a wire fishing tool to the recommended tools list though.


Outstanding customer service, communication, shipping, and prices were great.


Product was as expected and as described. Easy to install. Used to tow a utility trailer by Jeep Cherokee, a alwn mower at times and was used once to haul load of furniture in my son's move. Would recommend it to persons needing an after market towins setup.

Continues to work well with no problems.
W. L - 06/07/2021


The wiring harness fits perfectly, and was super easy to install. I have no complaints, and the team at were great to work with, super fast service!

Fantastic, no issues!
JEFFREY D - 11/02/2018


Easy to install and works great


Fix perfectly, but I ran the power cord inside instead of following the instructions. It fit under the trim and there was a “spare” grommet to run it through the firewall. Overall I’m very happy with the whole transaction! Thanks again etrailer!

No issues, I’m happy! I kept all the wiring inside so it doesn’t get exposed to snow and salt.
Gord - 04/02/2019


We were very pleased with our order from etrailer (hitch receiver + wiring). They took the time to ensure the wiring harness didn't rattle around in the package with the receiver and filled our order in record time. While we will be only using it occasionally, having an easy to install tow package will help us move those bulky loads with ease. Thanks etrailer!


Got this and the instructions seem very easy but haven’t had the need to install it yet.


Product works and instructions were pretty good. Instructions could have been a little better on some points: 1) Routing power wire to the battery could use a suggested route. 2) No mention of the access panels that are available on 2016 CX-5, which makes getting to the rear light sockets a breeze. 3) Suggest a good place to attach the control module so the harness doesn't end up too short to reach the hitch area.
I found a YouTube video that filled in the gaps.


This is the third hitch that I have purchased from All have been exactly as ordered and, although I have not had time to install the new hitch, I am certain it will fit. The detailed installation instructions and online videos make it impossible not to do it correctly and easily. The same goes for the wiring harness that I ordered. I have never installed one before but, after watching the video, it looks like a piece of cake.


I purchased the hitch bracket and the wiring harness for a Mazda CX5. Was very satisfied with the quality of the product. Both packages were complete without parts missing. Installation went very smoothly, recommend two people to install the hitch as it is cumbersome trying to hold it in position and start the nuts on the bolts. Very satisfied with the end result.

2008 Ford Escape

Everything arrived on time and well packaged. The wiring install went exactly as described in both the written and video instructions. The main reason I purchased from was the quality of the information on the products and installation. Couldn't be happier with the process from beginning to end. And the new hitch and wiring looks and works great!


Very easy to install


Have received but have not installed at this time. Quality is very good and I am looking forward to installing it.

Doug W - 10/14/2018


As good as the product itself are the videos available pertaining to the installation of the product and related items. I viewed them all. Excellent subject matter with complete instructions.


Easy to install. The etrailer product video was extremely helpful for me, since I have limited experience with wiring.


This harness was purchased for my grandsons vehicle. As far as know it has worked great. As far as installation ? He installed it. I didn't hear any complaints.
Great products !!!!!


The wiring harness was a perfect fit for my SUV and works as expected. Instructions could be more detailed but I found Youtube videos that showed the installation process.

Show More Reviews

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

  • Should Power Wire of Trailer Harness for 2016 Mazda CX-5 Run to Battery
    On some vehicles like your 2016 Mazda CX-5 it has been determined that the electrical system cannot or should not handle the load from its own tail lights and the trailer lights as well so they need a powered converter. These converters like the Tow Ready Wiring harness part # C56310 get power for the trailer lights primarily from the vehicle battery. This protects the vehicle electronics. They only use your vehicle taillights as signal wires. If you ran the wire to the power source you...
    view full answer...
  • Trailer Wiring Harness Recommendation For 2016 Mazda CX-5
    According to my contact in the Tech Services department at Curt Manufacturing, the correct taillight wiring harness for your 2016 Mazda CX-5 is part # C56310. The # C56310 uses the same plugs as the C56011, but the C56310 is a powered converter that draws the power to illuminate the trailer lights directly from the vehicle battery. Curt's engineers found during testing that due to the high amperage draw when the non-powered wiring harness C56011 was used, problems occurred with the vehicle's...
    view full answer...
  • Tips for Running Power Wire of Curt Trailer Wiring Harness on a 2016 Mazda CX-5
    I don't have specific instructions for the power wire but when routing a power wire for a powered converter like the part # C56310 the key is to route the wire away from any moving parts or exhaust that would get too hot and melt the wiring. If you can run the wire down a frame rail that would be ideal since that would protect the wiring somewhat. I attached a help article that covers how to route the power wire for a converter.
    view full answer...
  • Why Does Trailer Wiring for a 2016 Mazda CX5 Have to Run to Vehicle Battery
    The reason the Curt Custom Fit Vehicle Wiring # C56310 has a power wire is to protect the delicate tail light wiring circuits of your vehicle from being overloaded. The Curt Trailer Harness # C56310 that you referenced uses your tail light circuits as signal wires and then draws the power to illuminate the tail lights of your trailer directly from your vehicle battery through the battery wire of the box. Not doing this will void the warranty of the kit. I attached installation instructions...
    view full answer...
  • Does Trailer Wiring for 2016 Mazda CX-5 Require Running Wire up to Battery
    Yes, the trailer wiring kits that fit your 2016 Mazda CX-5 like the Curt # C56310 that you referenced do require running the power wire up to the vehicle battery. This is true for all kits that fit your vehicle as well as taillight configurations.
    view full answer...
  • T-Connector Vehicle Wiring Harness For 2016 Mazda CX-5 With LED Lights
    The correct Curt wiring harness for your 2016 Mazda CX-5 is part # C56310. The connectors changed between 2015 and 2016 for the CX-5 and the # C56011 will not work with your 2016. Per my Curt contact, the # C56310 will work fine with the LED lights on your CX-5. You just need to access the wiring connection points in the rear cargo area and then run a hot lead to the car battery. This harness includes a tail light converter that keeps the electrical system on your vehicle from being overloaded.
    view full answer...
  • Curt Trailer Wiring Harness on 2016 Mazda CX-5
    The # C56310 is the confirmed fit to work with all models of the 2016 Mazda CX-5. I verified with Curt that the # C56011 is compatible up through 2015 but will not work on the 2016 with or without LED lights. The connector used on the 2016 is different.
    view full answer...
  • Recommended Class III Trailer Hitch & Wiring for 2016.5 Mazda CX-5
    We just recently confirmed with Curt that their 2-inch Class III hitch # C13315 will indeed fit the mid-year version of the 2016 Mazda CX-5. The noted fit exclusion was temporary, until Curt engineers could get their hands on the 2016.5 to test fit this hitch. Our hitch pages will be updated shortly. If you also need a 4-pole wiring harness you can use Curt kit # C56310. This is illustrated in the linked review video and the linked article will assist your installation.
    view full answer...
  • Availability of Trailer Hitch & Wiring for 2016.5 Mazda CX-5
    We just recently confirmed with Curt that their 2-inch Class III hitch # C13315 will indeed fit the mid-year version of the 2016 Mazda CX-5. The noted fit exclusion was temporary, until Curt engineers could get their hands on the 2016.5 to test fit this hitch. If you also need a 4-pole wiring harness you can use Curt kit # C56310. This is illustrated in the linked review video and the linked article will assist your installation. Several helpful videos and articles are linked for you.
    view full answer...
  • Which Curt Trailer Wiring Harness Fits 2016 Mazda CX-5
    For the 2016 Mazda CX-5 the correct Curt trailer wiring harness is the part # C56310, the part # C56011 that you referenced was a fit for the year prior but the vehicle taillight connectors changed in 2016 so they had to release a new wiring kit. I attached an install video for this harness for you to check out as well.
    view full answer...
  • Does the Curt T-Connector C56310 Fit a 2016.5 Mazda CX-5
    The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # C56310 is in fact the correct trailer wiring kit for your 2016.5 Mazda CX-5. It will work with the LED lights on your trailer. I have attached a video of this kit being installed on a similar CX-5 that you can use as a reference. If you do not already have a hitch receiver on your CX-5 then I recommend installing the Draw-Tite # 76138 as it has a 2 inch hitch receiver which is compatible with many more applications...
    view full answer...
  • Recommended Mounting Bracket for 4-way Wiring Harness on a 2016 Mazda CX-5
    I can help you figure out a way to conveniently store your wiring harness # C56310 when not in use on your 2016 Mazda CX-5. It sounds like your mechanic ran the 4-way out of the vehicle and its hanging just below the hitch. For this I recommend a no-drill mount bracket like # C57202 and 4-way mounting bracket # 18144. I have linked a video of our installer installing this bracket on a similar hitch if you skip to the 13:42 minute marker, he will show you how this can be installed on...
    view full answer...
  • Is Drilling Required To Install the etrailer Hitch e98902 On a 2016 Mazda CX-5
    The etrailer Trailer Hitch Receiver part # e98902 which is a fit for a 2016 Mazda CX-5 does not require any drilling into the frame. There is also no trimming required for installation so there will be no permanent modifications. The trailer hitch is very easy to install, taking most only 30 to 40 minutes. If you will be towing then you'll also need the Curt T-Connector Vehicle Wiring Harness part # C56310 which is plug-n-play and the etrailer Ball Mount Kit part # 989900 which has all...
    view full answer...
  • Troubleshooting Trailer Lights Not Working Towing With Mazda CX-5
    There can be issues like this on some trailers using LED lights where they don't work at all. More than likely your LED lights aren't drawing enough power and this is the reason the tester works but not the lights on the actual trailer. This also varies between vehicles which would explain why it works on the truck and not your CX-5. In order to simulate more current draw, you can use load resistors like the # DI34ZR. You will need one per circuit so in this case 3 for the right turn/stop,...
    view full answer...
  • Curt Trailer Wiring Harness # 56310 Not Fitting 2016.5 Mazda CX-5
    It is possible that the tail light connectors on your 2016.5 Mazda CX-5 are the same as what is on the 2017 models. If that is the case it would take harness # C56377. Take a look at the connectors for this harness to see if they match up to what is on your vehicle. If not then the only other option is to use a universal wiring harness such as # 119190KIT and splice it into the tail light wiring on the vehicle. You should not have to break any tabs or modify anything to get a T-connector...
    view full answer...
    Image 1 for
  • Trailer Hitch Receiver and Wiring Harness for 2016.5 Mid-Year Model Mazda CX-5 with LED Lights
    Neither hitch receiver require a particular wiring harness. The wiring harnesses recommended match the manufacturer of the hitch. With Curt Hitch # C13315 we recommend Curt Wiring # C56310. With Draw-Tite Hitch # 76138 we recommend Tekonsha Wiring # 118563. Draw-Tite and Tekonsha are owned by the same parent company. Technically either wiring harness can be used with either hitch and they both work with LED lights. Curt does require a support strap # 18050 when carrying a bike rack...
    view full answer...
  • Can Parts To Tow Trailer With 2016 Mazda CX-5 Be Transferred To Another Vehicle
    I do have some great options for a 2016 Mazda CX-5 but most of these options (trailer hitch and basic wiring) are all designed specifically for said vehicle (custom fit) which is what allows you to install them without drilling into the frame or splicing into the vehicles wiring harness. I have attached a list below but some will be able to be transferred (universal fit). Draw-Tite Max-Frame Trailer Hitch Receiver part # 76138 (Custom Fit) Curt T-Connector Vehicle Wiring Harness part #...
    view full answer...
  • Which Receiver Has Best Height and Bumper Clearance for 2016.5 Mazda CX-5
    The Curt Trailer Hitch Receiver Item # C12170 is the hitch recommended to tow your small lightweight boat. It has a 1 1/4" receiver opening and is a confirmed fit for your 2016.5 Mazda CX-5. it has a maximum gross trailer weight of up to 3,500 lbs and a maximum tongue weight of up to 350 lbs. (Be sure to check your owners manual for vehicle towing specs) Both the available hitches have around the same inside top edge of the receiver tube opening clearance. But the Curt Trailer Hitch Receiver...
    view full answer...

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Info for this part was:

Employee Jackie C
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Employee Jameson C
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Employee Jeffrey L
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Employee Lindsey S
Edited by:
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