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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
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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. Lowest 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 800-298-1624 for expert service.
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  • Reviews (247)
  • Q & A (0)
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  • Why etrailer?

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 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   (247 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.

- C57672
by:

Installation was easy and intuitive. This fit my 2008 Subaru Outback wagon with zero problems. The hardest thing was removing the muffler hangers, but a little penetrating oil and channel locks made that much easier.



- C57672
by:

Perfect fit and easy to install. The only thing I would change is the 4 way flat connector tends to fall out of its holder. Not a big problem. It just need a little help to keep it in place.



- C57672
by:

I was fortunate to be one of the ones to order and eventually receive a 2021 Ford Bronco First Edition. Strangely enough, that meant that I was not able to order certain accessories with it one being the Tow Package. I contacted etrailer and explained what I was trying to do (hitch and 7Pin and they sent me a list of everything I needed to make it work



- C57672
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.



- C57672
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.



- C57672
by:

I would really like to give 5 stars, but can't. They have great videos on Installation, but none on New Jeep Wranglers. Can't figure out the Wire for Brake switch , so I'm Stumped unless I want to pay Dealer a crazy amount Green.



- C57672
by:

the 7 to 4 adapter it’s not specific for this car and hitch. the tongue to open the lid stick out to far not allowing the removable car bumper cover to fit.I had to cut the tongue of the lid in order to fit the cover


Comments
Thank you for your feedback. You can use a mounting bracket like part # C57202
Curt No-Drill Bracket for 6-Way or 7-Way Round Trailer Connector Mounting Bracket - Long
$16.28
to attach the harness to the hitch versus using the bumper.
-- Etrailer Expert Jenny N - 11/09/2021


- C57672
by:

Fit and function as stated. Mounting bracket could be a bit thicker. Including a few pieces of adhesive lined shrink tubing for the standalone wires would be useful.



- C57672
by:

Works well. Wish the screws holding the plate on wouldn't have rusted so quickly.


Comments
I recommend using a rust resistant paint from time to time to help prevent rust. Over time the metal brackets will tend to rust.
-- Etrailer Expert Jenny N - 05/12/2022


- C57672
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.



- C57672
by:

Easy installation works great!



- C57672
by:

Super easy to install! Works perfectly!


Comments
After one year still working like new!
Kevin - 05/14/2022


- C57672
by:

All connections were great! Could not find a great location for the plug!



- C57672
by:

Easy install, everything was quality but you will need your own self tapping screw which I think should have come with it



- C57672
by:

Very simple straight forward installation on 2000 F150 regular bed. Works great and was as simple as unplugging 1 connector and connecting the new adapter.



- C57672
by:

this product was exactly what I needed and I could not obtain from a local supplier. Price was right. It arrived within a reasonable time frame, install directions were clear and the initial install was simple and I had connectivity right away. I was able today to test with the trailer attached and it all works. Thanks,



- C57672
by:

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



- C57672
by:

Installed on my 2011 F150, part worked great as advertised on install. The 4flat adapter was easy and obviously ground too. However, the Ford truck has the wiring harness for the rear components sitting about 12”-16” away from where you would realistically want the 7 way mount to sit. I’m sure many other vehicles are this far away as well. Therefore to get to the remaining 3 wires I had to add in another roughly 8” of wire to each introducing some extra connectors and more areas for failure. Not too big of a deal but I would say for this parts blue, black, and yellow cord you should make them another foot longer that way they seamlessly work on any vehicle and the buyer just has to zip tie the excess out of the way on installation. Wouldn’t cost y’all much but would save time and effort for the customer. Otherwise great part, easy install, and good install videos as well



- C57672
by:

Great addition to our van. We need a 7 plug for our camper and the fact it has a 7 plug and 4 plug and mounts to the hitch is a huge selling point for me.



- C57672
by:

Reason not 5 star is as other review, not hooked up yet to check performance. Other wise everything else was 5 star. Phone call about products, emailed question was answered quickly.



- C57672
by:

Needed the adapter for our trailer. Just what we needed!



- C57672
by:

Great deal and fast shipping like always



- C57672
by:

I am very pleased with all aspects of this purchase- responsiveness of retailer, cost of product, prompt delivery and quality of item.



- C57672
by:

E-trailers honest and accurate descriptions of their products makes it easy to select what is required to suit the task at hand. They are my go to source to keep me safe & avoid getting traffic tickets. Great service too.



- C57672
by:

This was a little bit of work to get set up (considering I was also adding the 4 way flat as well, as the truck didn't have any trailer wiring, maybe not that bad) Worked out very well


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Ask the Experts 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...
    view full answer...
  • 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.
    view full answer...
  • 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.
    view full answer...
  • 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.
    view full answer...
  • 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...
    view full answer...
  • 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...
    view full answer...
  • 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...
    view full answer...
  • 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.
    view full answer...
  • 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...
    view full answer...
  • 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.
    view full answer...
  • 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.
    view full answer...
  • How Does 7-Way Trailer Adapter with 4-Way Connector Install
    What you have pictured is a 4-way to 7-way adapter similar to part # C57672. The male side 4-way connector plugs into a vehicle side (female) 4-way to convert the vehicle's connector to a 7-way. The existing 4-way on the vehicle only has the lighting functions so the rest of the wires need to be hardwired to make the 7-way completely functional. The additional wires are to power reverse lights (yellow), the 12 volt auxiliary pin (black), and electric brakes (blue). The white wire is...
    view full answer...
    Image 1 for
  • 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...
    view full answer...
  • 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.
    view full answer...
  • 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...
    view full answer...
  • 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.
    view full answer...
  • 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...
    view full answer...
    Image 1 for
  • Curt 4-Way to 7-Way RV and 4-Way Flat for 2016 Chevrolet Equinox
    I recommend the Curt Trailer Connector Adapter # C57672, 4-Way to 7-Way RV and 4-Way Flat. What I like about this is that it provides you the needed 7 way but extends out the existing 4 way making both available. Please note that while this will allow the 7 way to plug into vehicle it will still only support the lighting functions of the 4 way. If you want full functionality of the 7 way you will need the Universal Installation Kit for Trailer Brake Controller # ETBC7 as well. Please...
    view full answer...
  • 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...
  • Are Curt 4-Way to 7-Way Adapters The Same & Basic Brake Controller For 2021 Subaru Outback
    That's a good question and the answer is yes, the Curt Adapter 4 Pole to 7 Pole and 4 Pole with Test Lamps # C57674 is the same as the Curt Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat # C57672 but with the exception that one has test lamps and the other does not. Otherwise, they serve the exact same function as a 4-way to 7-way adapter. As for the brake controller for your 2021 Subaru Outback, since you are looking for something simple and basic, I recommend going with...
    view full answer...
  • Class V Trailer Hitch For A 2021 Toyota Tundra
    We have the Curt Trailer Hitch Receiver # C15398 for your 2021 Toyota Tundra. This is a class V hitch like you mentioned your wanted, that a maximum GTW of 16,000lbs, and a maximum tongue weight of 2,400lbs. If you don't already, you're going to need trailer wiring. I recommend upgrading your 4 pole connector, with the a 7 way trailer connector like # C57672. This kit plugs directly into your existing 4 pole flat connector and adds the functionality of a 7 way connector while retaining...
    view full answer...
  • Troubleshooting No Power on Curt Echo When Plugged Into 7-Way on 2012 Honda Odyssey
    It sounds like your Curt Echo # C51180 is not working after installing the T-One Vehicle Wiring Harness # 118521 and the Curt Trailer Connector Adapter # C57672. Assuming that is correct, you will be lacking the 12V power. More than likely the power reading came from a pin associated with the 4-way and the trailer lights. In addition to the wiring harness and adapter you would also need to add additional wiring or the only functions you will have on your 7-way adapter will be the 4-way...
    view full answer...
  • Will Curt Wiring Harness Fit With Draw-Tite 7-Way Mounting Box
    Both Curt wiring harnesses, part # C57674 or # C57672, will fit with the Mounting Box # 18156. The only problem is that these also come with 4-Way connectors as well which the mounting box doesn't have provisions for. I recommend using the Curt Wiring # C57674 along with the No-Drill Mount Bracket # C57202 which uses a similar strap to mount around the crossbar as the mounting box does. The difference in this case is that the bracket that comes with the Curt wiring is designed to accommodate...
    view full answer...
  • Replacing 7-Way Trailer Connector On a 1991 Chevrolet Suburban
    For your 1991 GMC Suburban V1500 we have the Curt T-Connector Vehicle Wiring Harness # C55312 4-way flat connector that will plug and play into the factory connections. As there is not a 7-way connector with the factory connections you can use the Curt Trailer Connector Adapter # C57672 to tie into the reverse light and charge line wiring wiring on the rear of your Suburban. You will be able to connect the 4-way harness directly to the adapter to take care of the running lights, turn...
    view full answer...


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Info for this part was:

Employee Mike L
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Employee Lindsey S
Edited by:
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Video Edited:
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