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Curt Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat

Curt Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat

Item # C57672
Retail:$72.00
Our Price: $35.87
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Trailer Wiring
Shipping Weight: 1.3 lbs
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This multi-function, vehicle-end connector converts any 4-way flat, vehicle-end plug to a combination 7-way outlet and 4-pole flat outlet. Great Prices for the best trailer wiring from CURT. Curt Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat part number C57672 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (382)
  • Q & A (0)
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CURT Trailer Wiring - C57672

  • Wiring Adapters
  • Multi-Function Adapter
  • 4 Flat
  • 7 Round - Blade
  • Plug and Lead
  • 4 Flat
  • CURT

This multi-function, vehicle-end connector converts any 4-way flat, vehicle-end plug to a combination 7-way outlet and 4-pole flat outlet.


Features:

  • Adapts 4-way flat to both 7-way RV and 4-way flat
    • 4-Way flat output connects tail lights, brake lights, and turn signals
    • 7-Way connects tail, brake, reverse, turn signals, and auxiliary power
  • Dust covers keep connectors clean when not in use
  • Split loom keeps wires contained and well protected
  • Simple installation
    • Wiring harness plugs into existing 4-way flat connector and hardwires to existing wiring to get additional functions needed for 7-way
  • Included hardware and metal mounting bracket secures wiring to the vehicle or trailer hitch
  • 1-Year limited warranty


Specs:

  • Distance between bracket mounting holes center to center: 2-1/4"
  • Harness length: 17"
  • Yellow wire is for reverse lights
  • Blue wire is for brakes
  • Black wire is for 12 volt power
  • White wire is ground


57672 Connector Diagram



57672 Curt Multi-Function Socket - 7-Way RV Blade and 4-Way Flat - Universal Fit

Installation Details C57672 Installation instructions


California residents: click here


Customer Satisfaction Score:


Customer Reviews

Curt Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat - C57672

Average Customer Rating:  4.7 out of 5 stars   (382 Customer Reviews)

This multi-function, vehicle-end connector converts any 4-way flat, vehicle-end plug to a combination 7-way outlet and 4-pole flat outlet.

by:

Your site us very helpfull for information and support and i reallt apreciate etrailer for all tge purpose.good product ,help support,and fait delivery even heure in Canada.
Tgank to all of your team.i am presently installons the controller on my car after the installation i Will feed about how it work.
Have a nice day

Luc

7/30/2023

Very well great product,goid brake controll ,smooth,ibreally like the way it work,and Allo it take juste à small place under dash for me 10 star a grest product

Luc

7/30/2023

Great product the curt7pin with the 4 pin on the side really helpfull for installation good product ,to be sure keeping moisture away in the connector i Also use electric compound grease in it to prevent corrosion and still very good no connection problem yet even with the kind of weather we have here up North in Quebe crain ,snow,..good product well made.



by:

The connector fit the existing mount on my 2007 Dodge Ram 1500 bumper perfectly. Four bolts and nuts, plug in the wiring, and I'm ready to roll. Thanks, etrailer! Another great product!



by:

I used this on my 2017 RAV4. This harness provides me the flexibility of using flat-4 or a 7 way connector for towing flexibility. The RAV4 is a small tow vehicle and I like the added security of electric brakes even on lighter single axle trailers which the 7 way allows. I plugged this adapter into the flat-4 connector provided by the "T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector Item # 118578" and used heat shrink tubing around the crimp connectors for the brake controller wires to keep moisture out.



by:

THE people to go to for trailer and towing stuff. Myself and friends all order here, can't say enough about the great customer service, always getting the right parts, and the overall quality. It is always a pleasure.



by:

Great all in one unit



by:

Works perfectly. No problems at all.

Just
an FYI, the installer didn't hook up the reverse wire although we asked. This is a common practice according to our camper's manufacturer so be adamant with your installer if you want the wire connected.



by:

I had an existing 4 pin, this plugged in and gave me the 7 pin I needed for picking up my teardrop. I did not use the other wires and just taped them to the casing. Worked perfect.



by:

Good product overall, installed on my 2016 Volkswagen Golf to tow a 13' Scamp fiberglass trailer. Although do be attentive, as other reviews have stated, that using all the functions of the 7-pin connector (electric brakes on the trailer) may require extra work. In my case, it required running an extra lead from the car battery with a fuse in line. I was was able to run it through the body of the vehicle, although I gather it's also possible to run it under the entire vehicle. Just something to be aware of; as my first time towing anything, it was a learning curve to understand how to put it all together.



by:

This would be a 5 star rating if all my trailer plugs fit equally well. The preformed trailer wiring plugs are a perfect fit, (4 out of my 6 trailers have them), but two aftermarket plugs are a struggle to get the retention notch to fit inside cover hook that keeps the plug in place. ((Otherwise the plug pops out)).
Bottom line is I would buy this connector again because of the price point and ease of installation. From now on I will be buying the preformed trailer wiring harness for the perfect fit.



by:

Needed to slightly modify the bracket clearance holes to have the plastic holes line up properly and fit cleanly. Not a big deal but someone else may have struggled with that if they expected a simple install.



by:

Worked great for a while. Then the pins started to pull out and stick in the trailer plug. Have to pull them out of the trailer plug and push them back in.



by:

This is a great harness. And was easy to install and is still working great a year later.



by:

Fast shipping, clear instructions, easy install, works great.
Thanks!

Bones

2/9/2023

Still working! Thanks!



by:

Overall, satisfied. The installation videos were helpful, and the product seems quality. I only have one complaint, which is what kept this from being a 5 star review. This may be obvious to most people, but it wasn't to me. This WILL get you to a 7 pin connector, but there is a good bit more work to do to get all the functions of a 7 pin connector to work. Meaning, to get power to my 7 pin connector and trailer, I had to run a wire to the battery, and place a circuit breaker inline with that wire. Again, this may seem obvious to some, but it took some figuring out for me, and any time I asked this question to etrailer, they could never seem to give a straightforward answer. But for my Mazda CX-5, about 15 feet of 12 gauge wiring and a small fuse kit did the trick. Lots of splicing of course.



by:

Air lift installed on a 2018 Jeep Wrangler JKU with a 4” lift. Alison B put wanted to make sure I got the right bags and put me in touch with Air Lift who helped me get the correct bags. It was easier and quicker to remove rear springs and install the bags, just remember to apply lubricant to help with installation. Alison B was great to work with and extremely helpful in making sure I got the right parts. I have done business with etrailer in the past and will continue to use them in the future.



by:

I took my car over to the dealership and they sent it out to another shop. When he brought my car back, the electrical wires were installed upside down. It took the installer over 6 hours to install my receiver hitch.
It looks great now that I’ve turned the wiring the correct way to install your electrical wiring.



by:

Not even 2 years after install all rusty. Electric brake pin broke due to rust.
Impossible To remove 4 bolt holding connector due To rust. I do not recommend

Etrailer Expert

Katrina B.

7/19/2022

Its unfortunate that your pins and bolts are unusable due to rust. I see that you are located in Canada, we recommend making sure that you are using dielectric grease often to prevent and keep the rust from spreading along the harness. Unfortunately, rust is not covered under warranty, and even if it was, this is well passed the one-year warranty for this item. I would recommend contacting our customer service department for them to assist you in ordering a new harness, such as part # 118467.



by:

Put this on after #c56027 to change to 7-way rv plug as all my trailers have been switched to 7-way. 7-way is much easier to plug and unplug than 4-way. Easy to install. I have been using it once a week and it is working very well.



by:

Within 3000 miles the wires came loose from the connections and shorted the light system, unfortunately withing a few minutes of this happening, I was stopped by a office. I could have gotten a ticket but instead was given a warning. Had to re wire on the spot around the connections to be able to move the van.



by:

This sure made changing from the factory 4-way connector to a 7-way/4-way connector quick and easy. All I had to do after installation was to add wiring for the electric brakes and trailer battery charging.



by:

Great product! Only issue is lack of mounting holes (2) on top of metal bracket. Maybe they forgot to drill holes at the factory.



by:

Year later still great.



by:

Excellent product, good fit, high quali ty.



by:

Easy to install. No issues wiring up the harness



by:

Super easy install. Their installation video covers everything.piece of cake.
2016 Outback. Great first step in adding a 7way plug and brake controller.


25
382
Show More Reviews

See what our Experts say about this CURT Trailer Wiring

  • How to Use a 4-Pin to 7-way Trailer Connector Such as C57672
    The # C57672 will allow you to convert an existing 4 pin connector on a vehicle and allow it tow a trailer that has a 7-way. By attaching the mounting bracket to the underside of the bumper or chassis of the tow vehicle, plugging the 4 pin on the adapter into the existing 4 pin connector on the vehicle and attaching the white ground wire to the tow vehicle's frame or chassis, you'll be able to activate the lighting functions on your trailer. There will be three remaining wires on the adapter...
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  • Which Battery Terminal Do I install Black Wire Of Curt Trailer Adapter On My 1991 Ford
    Per instructions when installing The Curt Trailer Connector Adapter # C57672 on your 1991 Ford the black power cable will need to be attached to the red positive terminal on your battery per the instructions. This multi-function, vehicle-end connector converts any 4-way flat, vehicle-end plug to a combination 7-way outlet and 4-pole flat outlet. I attached a review video link below.
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  • Does 7-Way Adapter C57672 Have 4-Way Functions on 7-Way
    Yes, the 7-way adapter part # C57672 does give you the exact same features as the 4-way on the 7-way as well as this has a second 4-way on the side of it as well.
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  • Can 4 Way and 7 Way of Curt Trailer Connector Adapter # C57672 be Used at Same Time
    Yes, the 4-way and the 7-way of the Curt Trailer Connector Adapter # C57672 that you referenced can be used at the same time as they are both active at all times.
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  • Solution for Adapter for Vehicle 4-Way to Trailer 7-Way
    It sounds like you're looking for an adapter like the Curt Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat # C57672. The Curt adapter should be mounted to your vehicle. This will have both the 4-way and 7-way connection. Since it sounds like you don't need the 12V power or brake output you can leave the additional connections disconnected. All you will need to do is plug in your existing 4-way to the 4-way plug on the adapter. Once this is done, the 7-way connector will have...
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  • How To Install The Curt Echo On My 2013 Toyota Sienna With A 4-Flat Harness
    Since you already have the 4-flat harness installed on your 2013 Toyota Sienna, and have the adapter all you will need is The Wiring Kit for 2, 4, 6, and 8 Brake Electric Trailer Brake Controllers # 5506. I attached a review video link below.
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  • Wiring Harness for 2020 Dodge Durango Without Factory Tow Package
    Yes, the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector item # 118617 is a confirmed fit for your 2020 Dodge Durango without the factory towing package. The Tekonsha wiring harness plugs in line behind your Durango's rear tail lights to provide power and control over your trailers lighting functions. If you are in need of a 7-way vehicle connector than I recommend the Curt Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat item # C57672. This adaptor...
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  • Do the Blue, Yellow, and Black Wires Need To Be Run On the Curt Trailer Connector Adapter C57672
    For starters, we do not offer products through Amazon as they are a competitor of ours. However, I can offer you the Curt Trailer Connector Adapter part # C57672 which will work on your 1968 Ford F-150 if you have an existing 4-way trailer connector. The additional black, yellow, and blue wires do not need to be attached in order for the trailer light to work but you will need to ground the white wire to your frame. The black wire is to charge a battery on the trailer and you will need...
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  • How to Install 7-Way Connector on 2019 Subaru Outback Wagon
    We have exactly what you need to install a 7-Way connector on your new 2019 Subaru Outback Wagon so you can connect with the 7-Way on your trailer. You will need to start with a 4-Way harness and for this the Tekonsha T-One # 118467 will work perfectly. This custom harness will plug right into a factory port behind the driver's side trim panel for a completely "plug-and-play" installation. I have attached an installation video that you can even use for reference. Then once you have...
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  • Does Ground of 4-Way to 7-Way # C57672 Have to Be Ran for Just Taillight Functions
    If you were only planning on using the standard trailer taillight circuits with the # C57672 you would not need to run the extra ground wire although it wouldn't be a bad idea as it would add additional grounding to your trailer wiring. If you wanted to connect it you'd want to run it to the vehicle frame.
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  • No Voltage Increase on Brake Output Pin When Brake Pedal Pressed
    The Curt # C51180 Echo wireless brake controller is a proportional brake controller. A proportional controller senses the rate at which the vehicle is braking, and will then send the proper amount of voltage to the trailer brakes so that the vehicle and trailer brake at the same rate. Unlike the older, time delayed style brake controllers, you will NOT get full voltage on the brake output pin unless the brakes are applied while the vehicle in motion. This being said, you shouldn't be...
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  • Curt 4 to 7 Way Adapter for the Curt Echo Wireless Brake Controller
    You assumed correctly. The Blue and Yellow pigtail leads on the Curt Adapter Item # C57672 do not have to be connected to use the Curt Echo item # C51180. You will just need to connect the 4-way to the adapter and then run the ground and power wires.
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  • Does the Alarm Always Sound in Reverse on the Curt Trailer Connector Adapter with Backup Alarm?
    Any time your vehicle is placed in reverse, whether you are towing or not, the alarm will sound on the Curt Trailer Connector Adapter with Backup Alarm item # C57102. To have the same connector without the beeping sound you will want the Curt Trailer Connector Adapter item # C57672. This is the same 7-way and 4-way connector without the alarm. I have linked an installation video below.
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  • Factory Tow Package on a 2018 Mercedes GLC 300
    Yes, your 2018 Mercedes GLC 300 would have come with a functional 7-way if you have the factory tow package. The Curt Echo Wireless Trailer Brake Controller item # C51180 will work great in your Mercedes and you won't have to worry about running wires or permanently installing a brake controller.
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  • How To Convert 4-Way on Toyota Rav4 into 7-Way for Trailer without Brakes
    Yes, in order to convert the 4-way trailer wiring harness on your Toyota Rav4 into a 7-way trailer wiring harness you just need a simple adapter, the Curt Trailer Connector Adapter part # C57672 which features a plug-in install. The two 4-ways will plug into one another and then you'll have a few more wires to hook up. The white wire goes to ground and then the rest are optional. If the trailer does not have brakes, the blue wire can just be tapped up, the same goes for the yellow reverse...
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  • How Do I Install A 7-Way Connector On My 2020 Subaru Outback
    In order to setup your 2020 Subaru Outback with a 7-way connector, you first will need to have a 4-way connector installed on your vehicle. You can do both with the Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires, part # ETBC7. It will involve some wire splicing, but when you are done you will have the 7-way and 4-way options on your 2020 Subaru Outback. I have included two product description links and video links below.
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  • Wiring Harness Recommendation to Fit In-Line with HitchMount LED Pod Reverse Kit
    Thanks for reaching out! The HitchMount LED Pod Reverse Kit has the standard US Car Connector on it which is pretty common on most 7-Way connectors. It actually looks like the Curt Wiring Harness # C57672 you're looking at doesn't have this US Car Connector so for your application I recommend checking out the Hopkins Wiring Harness # 37185 which has the same basic wiring connections but also uses that US Car Connector you're looking at.
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  • Troubleshooting Left Turn Signal and Brake Light Not Working After 7-way Adapter Installation
    To answer your question, yes, it could be a bad ground. I would double check the ground from your 4-way as well as the ground for the 7-way adapter. Make sure they are securely attached to a clean, bare metal surface. You may even consider moving the ground from the recently installed adapter to a new position. The ground wire on the # C57672 should be secured directly to the frame. If that doesn't fix it, I would check all of the connections related to the left turn signal and make sure...
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  • How Does 7-Way Trailer Adapter with 4-Way Connector Install
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    Image 1 for
  • Adding A 7 way Plug To A 2019 Toyota Highlander With A Factory 4 Flat
    I can definitely help set you up. You can use the adapter like the # C57672 you mentioned. You can plug into the existing 4 flat plug. You would also need to run additional wires for a brake controller. We make a kit # 5506 specifically for this purpose. This will be everything you need to get the 7 way plug working. The last thing you need will be a brake controller. For that I recommend the Tekonsha Prodigy P3 # 90195. This brake controller is very user-friendly and will be easy to...
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  • Is Curt 4-Way to 7-Way Adapter C57672 Compatible with 4-Way C56452
    Yes the 4-way to 7-way part # C57672 is compatible with the 4-way kit part C56452 # C76CR that you referenced.
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  • Troubleshooting Overloaded Vehicle Harness On a 2015 Ford Transit T250
    That sounds correct to me. When you cut off the Curt T-Connector Vehicle Wiring Harness # C56327 converter box, it tried to pull all the power for the trailer circuits off the vehicle harness on your 2015 Ford Transit T250. It hopefully only damaged the fuses and not parts of the vehicle harness. Be sure to check the power wire that ran to the converter and see if the fuse was damaged or any of the harness is damaged as that would explain why it was not working when you recently tried to...
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  • Since The Curt C56407 Harness Already Has A Power Wire, DO I need To Run Another One For A 7 Way?
    The black power wire on the # C56407 is just for the powered converter as not all vehicles can handle the additional amperage draw of trailer taillights. This line will not provide the needed power for a battery or other accessory on your trailer, so you will need to run both. But on the plus side, already having the one line run will make running the second one for the # C57672 a lot easier. If you do not already have the wiring needed to do this, the Wiring Kit # 5506 will include all...
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  • How To Connect Curt Adapter 4-Way to 7-Way RV and 4-Way Flat To Battery on 2008 Jeep Wrangler
    In order to attach the Curt Adapter # C57672 to the battery you will need to run some wire. Our # ETBC7 kit comes with everything you need in order to complete this install. If you already purchased the adapter, the Wiring Kit for 2, 4, 6, and 8 Brake Electric Trailer Brake Controllers # 5506 should have the additional hardware and wire you need. The 25' of 10-2 Duplex wire will connect to your adapter and run to your battery and brake controller. For the battery, you will need to connect...
    view full answer...

Do you have a question about this Trailer Wiring?


Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Jameson C
Expert Research:
Jameson C
Employee John H
Expert Research:
John H
Employee Adam R
Expert Research:
Adam R
Employee Lindsey S
Edited by:
Lindsey S
Employee Joshua S
Video by:
Joshua S
Employee Dustin K
Video by:
Dustin K
Employee John S
Video by:
John S
Employee Thomas T
Video by:
Thomas T
Employee Jacob T
Video Edited:
Jacob T
Employee Cole B
Installed by:
Cole B
Employee Ryan G
Installed by:
Ryan G
Employee Wilson B
Updated by:
Wilson B
Employee Noah M
Updated by:
Noah M
Employee Conner L
Test Fit:
Conner L
Employee Bradley B
Test Fit:
Bradley B
Employee Kristina F
Written by:
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