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Buyers Products Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat

Buyers Products Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat

Item # 337TC1474P
Our Price: $21.18
You Save: 43%
Trailer Wiring
Shipping Weight: 1.21 lbs
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Buyers Products Wiring Adapters - 337TC1474P
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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 Buyers Products. Buyers Products Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat part number 337TC1474P can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (97)
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Buyers Products Trailer Wiring - 337TC1474P

  • Wiring Adapters
  • Multi-Function Adapter
  • Plug and Lead
  • 0 - 5 Feet Long
  • 4 Flat
  • Buyers Products

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.


  • 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 are dirt and weather-resistant
  • Split loom keeps wires contained and protected from the elements
  • 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 warranty


  • Distance between bracket mounting holes center to center: 2-1/4"
  • Harness length: 10"
  • 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

TC1474P Buyers Products 7-Way Dual-Plug Trailer Connector with 10 Inch Prewired Harness

Customer Satisfaction Score:

Customer Reviews

Buyers Products Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat - 337TC1474P

Average Customer Rating:  4.8 out of 5 stars   (97 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.


I paired this product with product number C56349 for my 2016 Toyota Tacoma in order to tow a teardrop trailer which has trailer brakes. After installing the 4-way plug (C56349 is extremely easy to install), installation of this item was a breeze. I’m very happy with this product and look forward to towing my teardrop


this adapter seems to be what was said that i has been working for three days,easy to put on and looks good.guess thats what everyone calls "plug and play "


The whole ordering process was excellent. William was great in assisting me select the correct parts for my trailer hook up.


So I placed an order for a 4 pole converter and etrailers contacted me quickly and let me know my order was backorded a little but they had a matching product that was cheaper. As they changed my order they realized I ordered the wrong ending and fixed that also. Arrived today and everything fit as they said it would. Excellent


Great product, allows me to use either 4 or 7 pin connector on my 02 Dakota.


I don’t use anyone but etrailer for towing accessories, these guys have good prices and great products. This adapter works great and is easy to install. 10 out of 10!


I had technical questions. I called and they help me find the right part that was less money than my original item I was going to buy


We’ll designed


It worked great on my 01 Silverado. The only thing I didn't like is the way the 4way plug just slides into bracket with nothing securing it.Other than that was easy install.


etrailer knew exactly what I needed good knowledge and specific. great customer support arrived on time.


Perfect for my application. I give it 5 stars. Quality is good and the price is reasonable.


Paula did a fantastic job recomending parts needed to make the job easy!!!!! Took the time needed, didn’t rush me, BRAVO!! Thanks!


Part worked as advertised. Excellent service to replace a part that what incorrect. etrailer will always make it right! That is important for DYI guys like me.


Good product easy installation and dummy proof.


Awesome service and fast delivery


Tech support led me to the perfect solution for my needs - thank you!


Price was right, but not the quality of design. The 4-way plug sits into an open-sided area on the mounting bracket, a loose fit and never stayed in place. I had to remodel, cut a piece of tin and pop-rivet to bracket, to trap 4-way plug and keep in place. Spending a little more money gets you something that works at the get-go.

Jenny N.


I recommend part # C58000 as an alternate bracket. It clamps to the hitch receiver and also provides a four-way clamp that will hold the 4 flat more securely.



Etrailer Expert

Brooke M.


I have heard of folks wrapping electrical tape around the plug to help it sit more snuggly. What I recommend is getting a new plug for your trailer. We carry part # PK12706 which is just the plug so that you arent having to redo any wiring.


Super easy to install, works great!


Been using for years now. We have a pop up camper with a 7 pole connector, bit the standard kits never seem to be available with a 7 pole connector. This is super easy to install on the stock 4-pole connector.

Definitely pick up the kit that allows you to run power to the connector. It's a Curt 55151, "Powered converter wiring kit".

This will allow you to charge your battery while driving.


Worked out well. Only issue when installed on lower frame by hitch bending wire bundle to left to hook up and tie up. Bend behind receptacle is approximately one and a half inches from muffler due to its location, hopefully it will not get too hot.


Worked as described


I haven't installed it yet but looks go od


Well made product that works perfectly. Only 3 stars because the bracket doesn't hold the 4 pin plug well enough, it's very loose.


This is a solid 7 way adapter which I would recommend. You will need to buy a 12V wire and fuse to connect to your battery, or buy a kit that comes with these parts. I did not need those as this was a replacement for 7 way adapter I had already installed but damaged.

4 stars because
- The 4 way plug just pops into a slot next to the 7 way connector but there is nothing that keeps it there. So it feels like it could fall out.
- The included crimp connectors are the standard type, not the water resistant type.

Show More Reviews

See what our Experts say about this Buyers Products Trailer Wiring

  • Can I Use Buyers Products Trailer Adapter For Just the 4-Way Functions
    Yes, you can plug your existing 4-way into the 4-way pigtail of the Buyers Products Trailer Connector Adapter part # 337TC1474P and ground the 7-way plug to a clean bare metal surface on the frame. You can tuck the black, blue and yellow wires away. The 4-way plug on the adapter will allow you to plug in a trailer that uses a 4-way trailer connector.
    view full answer...
  • 4-Way to 7-Way Adapter to be Used with Trailer with 7-Way and Tow Vehicle 4-Way
    Tow tow a trailer that has a 7-way with a vehicle that has a 4-way will require an adapter like the # 37185 which the vehicle 4-way plugs into and then is converted to a 7-way like what the trailer needs. There really isn't a different style adapter that would work so this would be what you'd need.
    view full answer...
  • 7-Way Vehicle Wiring Plug Bracket For Mounting on 2016 Mercedes-Benz Sprinter
    I recommend using a Curt No-Drill Bracket # C57202 that will allow you to attach the Buyers Products Trailer Connector # 337TC1474P to your 2016 Mercedes-Benz Sprinter hitch. This bracket uses a clamp and will not require you to drill into the hitch. I have attached a video below that will show what this bracket will look like on a 2014 Sprinter.
    view full answer...
  • Can The Buyers Products Trailer Connector # 337TC1474P Be Mounted on The Trailer?
    Yes, the Buyers Products Trailer Connector Adapter # 337TC1474P can be mounted to your trailer. This is what some use in a tandem trailer tow situation. Or you could use this with a Double-Ended 7-Way # 50-67-210 to connect on both the vehicle and trailer.
    view full answer...
  • Troubleshooting Plug Configuration on Hydrastar Vented Marine Electric Over Hydraulic Actuator
    The Hydrastar Vented Marine Electric Over Hydraulic Actuator for Disc Brakes # HS481-8067 is designed to be used with vehicles that have a factory OEM brake controller, which would mean there is already a 7-way on place. If your truck did not have a 7-way then you would not have the OEM brake controller. There are different 7-way options, it sounds like you may have picked up the wrong size from your auto parts store. You would want a 7-way like the # 337TC1474P. The only 3 pin plug that...
    view full answer...
  • How Can I Get Both A 7 Way and 4 Flat Plug On My 2018 Toyota Tacoma?
    I can definitely help set you up! First we set you up with a 4 pin T harness like the # C56349. This will plug in behind your tail lights and give you a 4-flat connector on the back. From there you can use our universal upgrade kit # ETBC7. This kit will come with absolutely everything you need to upgrade the 4 pin connector to a 7 way. The plug we include with this kit is part # 337TC1474P which will have both a 7 way and 4 way that you can hook up to. Once the # ETBC7 kit is installed...
    view full answer...
  • Replacement Trailer Connector For 7-Way RV Upgrade Kit ETBC7 and ETBC7L
    You can use the Trailer Connector Adapter # 337TC1474P to replace your connection as we do not have a replacement cover for the 7-Way RV Upgrade Kit # ETBC7L. The new connector will plug in just like your current unit and has the same 4-way and 7-way connectors. You will only need a set of Wiring Pliers # PT43ZR to cut the old power wire and install the new connector. Be sure to disconnect the battery before cutting any wiring.
    view full answer...
    Image 1 for
  • 2018 Ford F150 Hitch 4-way to 7-way Trailer Connector
    If you need to connect to a trailer that has a 7-way but does not have or need brake signal, 12V power, or a reverse signal then you can the # 337TC1474P connector. It plugs into your existing 4-way and then you can tape the other wires up out of the way. I have included a video of this being installed with another kit on an SUV and at the very end of the video you can see this 7-way being installed. To get a fully functional 7-way on your 2018 Ford F-150 with a factory 4-way, you will...
    view full answer...
  • Trailer Hitch For 2018 Lincoln MKT For Towing a 4,000 Lb Trailer
    I was able to confirm that the Draw-Tite Max-Frame Trailer Hitch Receiver part # 75679 is a fit for the 2019 Lincoln MKT which is the only option. It is a great option with a custom fit design that does not require drilling into the frame of the Lincoln MKT. This will give a 2" receiver on the Lincoln that can tow 4,000 lbs however you do want to check the owner's manual to make sure you can tow 4,000 lbs safely. For the trailer wiring, I recommend 7-way plug part # A10-7072VP which will...
    view full answer...
  • Can I Add a 7-Way Plug to the Curt Tail Light Converter with 4-Pole Flat Trailer Connector C59236
    Yes the Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector part # C59236 does have a 4-way flat that can be turned into a 7-way connector. For just basic lighting functions the Buyers Products Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat part # 337TC1474P is a great choice that will give you stop, turn and running light functions. If you want a 12 volt powered plug go with part # ETBC7L and for a fully functioning 7-way that would have lights, trailer...
    view full answer...
  • Adding a Charge Line Circuit To a Trailer With a 4-Way/5-Way Flat Connector
    I recommend moving away from the Adapter 4-Pole to 5-Pole Trailer Wiring Adapter # 47515 and going with a Buyers Products Trailer Connector Adapter # 337TC1474P. The wiring and connectors used on the 4-way harness are not designed to be used with the 20amps of power you will putting on the connector. The 4-way/5-way connector cannot handle the additional strain and it will likely overheat with the amperage and risk causing an electrical fire. With the Buyers Products Trailer Connector...
    view full answer...
    Image 1 for
  • Convert Motorhomes 4 Way To 7 Way And Install Charge Line For Towed Vehicle Battery
    If you do not have a 4 way flat and just have 4 wires at the back of your motorhome, then use Hopkins Endurance Quick-Fix Replacement 4-Way Flat Trailer Connector w LED Test Lights - Vehicle End # HM48190. This will connect your 4 wires to a 4 way flat plug. Once you have a 4 way flat, you can convert to 7 way with Buyers Products Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat # 337TC1474P7. Your 4 way flat will plug into the 4 way harness on this adapter, then you will need...
    view full answer...

Do you have a question about this Trailer Wiring?

Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Video Edited:
Jeff D
Employee Dustin K
Video Edited:
Dustin K
Employee Chris R
Video Edited:
Chris R
Employee Robert C
Test Fit:
Robert C
Employee John A
Test Fit:
John A
Employee Kristina F
Written by:
Kristina F
Employee Aidan B
Video by:
Aidan B
Employee Ethan H
Video by:
Ethan H

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