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Adapter 7-Pole Round Pins To 4-Pole Flat
Hopkins

Adapter 7-Pole Round Pins To 4-Pole Flat

Part Number: 47405
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Hopkins Single-Function Adapter Trailer Wiring - 47405
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Great Prices for the best trailer wiring from Hopkins. Adapter 7-Pole Round Pins To 4-Pole Flat part number 47405 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (37)
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Hopkins Trailer Wiring - 47405

  • Wiring Adapters
  • Single-Function Adapter
  • 4 Flat
  • Plug Only
  • 7 Round - Round
  • Hopkins


  • Plug-In Simple 7-way to 4-Way adapter
  • Incorporates an easy grip design and includes a dust cover for the 4-flat to help prevent corrosion
  • Impact and corrosion resistant
  • 90-Day warranty

47405 Adapter 7 Pole Round Pins To 4 Pole Flat

Installation Details 47405 Installation instructions


California residents: click here


Video of Adapter 7-Pole Round Pins To 4-Pole Flat

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for All About the Adapter 7-Pole Round Pins To 4-Pole Flat

Today, we're going to be taking a look at part number 47405. This is the Hopkins adapter, 7 pole round pins to a 4 pole flat connector. This adapter is going to convert your 7 pole round plug with round pins on your vehicle to a 4 pole flat trailer connector on your trailer. We take a look at the overall link measuring from the back to the front. Just going to give some measurement, about 4 and one eighth of an inch. It's made from a nice, durable plastic construction so it's very strong and durable.

It's also going to feature a nice impact and corrosion resistant design. Over here on this end by the finger tabs, you're going to have the 4 pole connection, that's going to come with the dust cap, so this is included to protect the 4 way connections when the plug's not being used. Simply just slides over there. You're going to have the large finger grips that's going to allow for easier installation and removal of the plug. It's also going to feature the tab here on top, that's called a lineup of the groove on your 7 pole plug for easy connectivity. Really nice design, and again, this plugs in to the 7 pole round plug on your vehicle, and then it's going to allow you to have the functions needed to power the trailer lights on your trailer that has a 4 way flat connector on it.

That's going to do it for our review of part number 47405. This is the Hopkins adapter, 7 pole round pins to a 4 pole flat. .

Customer Satisfaction Score:


Customer Reviews

Adapter 7-Pole Round Pins To 4-Pole Flat - 47405

Average Customer Rating:  4.6 out of 5 stars   (37 Customer Reviews)


by:

Came quickly, it was exactly the right adapter to hookup our older one to our new foldable Harbor Freight trailer Thank you!



by: 01/10/2024

This adapter is only for round pins. If the 7-pin connector on your vehicle has flat blades instead of round pins, this adapter will not work.

I'll give it five stars because I expect it works fine, I just didn't realize I needed to check the pins. No fault of the part.



by:

Plug and play for my project. LOL



by:

Didn't work precisely on my application, but the existing wiring was made for a custom trailer so I had to make some modifications.



by:

Got here in a timely manner and was just what we needed to get our notill drill on the road safely and legal



by:

Unfortunately, it does not fit my vehicle. It is too large in diameter. I should have measured that before ordering.



by:

You had what I needed and it arrived quick, good job folks



by:

My fault, wrong piece! Didnt know that there were different prongs! I need the 7 flat prongs with a 4 flat connection! Installed the wishbone wiring today, very pleased with that! Ran it all and connected to my new lights, been a long time coming, thank you so much



by:

The Adapter DOES NOT WORK on the running lights! It does work on brake and turning lights. I tested the pickup Receiver for the Adapter and the pickup works ok, however looking at the "Adapter hole side, with the guide up" the Adapter tail lights connector is the 2nd hole to the left But on the pick is the 1st hole on the left on the 1996 Dodge Ram 2500. (factory equipped). How do I contact you all on this?

Katrina B. profile picture
Etrailer Expert

Katrina B.

4/20/2022

It sounds like there might be a connection issue between the 4-pole to the adapter. We suggest that you test the 4-pole side of the adapter with the 7-pole connected to the vehicle. I have sent this information over to our customer service department for them to better assist you.



by:

Item arrived in great condition DAYS BEFORE it was expected. Great company to do business with. Any trailer needs I have going forwarded will be handled through etrailer.com!! Best company I've EVER done business with.



by:

I was having a hard time finding this trailer adapter and found it on etrailer.com! Exactly the right pin to pin configuration. The economy shipping was fast too. I received the adapter in a timely manner. Thank you



by:

I bought a truck wired with a 7 pin trailer receptacle so I went to 2 different stores locally to purchase an adapter. Striking out twice, I checked etrailer.com and sure enough it was available. I made the purchase, arrived in a couple days and made a perfect fit.



by:

I use this to adapt my tractor's power outlet to run a 12 volt sprayer. I just use the ground and light terminals. That way, when I turn on the Tractor's lights on the sprayer runs. Works great!



by:

This is a nicely manufactured and finished product, and comes with a cover for the 4-pin end of the plug. It is easy to use.



by:

Worked perfect for our 1993 Ford F-250 diesel. This is a 7 round to 4 flat accessory



by:

The adapter worked well, and I use it regularly. A good buy for the price.



by:

Dose what it's made for. Use it all the time :)



by:

Excellent ease of use, Exact product and quick FREE delivery.



by:

Good product, good people



by:

Good plug came quick and pic is great



by:

Great product and price



by:



by:

As advertised and works well



by:



by:

good price.


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Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring

  • Will the 7-Way Round Pin to 4-Flat Adapter Work On a Semi
    I do have an option for you but the 7-Way Round Pin to 4-Flat Adapter part # 47405 won't work on semi's as there is no converter integrated into the adapter. The lights on a semi are separate and the lights on a trailer are combined so a converter is required. Therefore, you will have to make your own adapter using the Hopkins Tail Light Converter part # HM48847, 7-Round Connector part # PK11700, and Hopkins Wiring Harness with 4-Pole Flat Trailer Connector part # HM48035.
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  • 7-Way Round to 4-Way Adapter with Thicker Ground Pin
    The pin sizes on your 7-way round connector are standard so what that means is that a standard 7-way round to 4-way adapter like the part # 47405 that you referenced would work Tom.
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  • Recommended 7 to 4-Way Adapter for a 2018 Volkswagen Atlas
    The best option we have for you would be to replace the trailer connector on your 2018 Volkswagen Atlas with the 7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket part # HM40975 which is a plug and play option. The reason that this is the best option for you is because adapters like the Adapter 7 Pole to 4 Pole with Tester and Cover part # 47345 can have different tolerances which is the only reason that I can think of as to why it will not work for you. These types of adapters...
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  • Adapting a 7-Way Trailer Connector on an RV to a 4-Way Flat on a Towed Vehicle
    If the coach uses the 7-Way RV style connector with blade style pins then you can use coiled adapter, # HM47065, with the Hopkins Custom Tail Light Wiring Kit, # HM56000, or similar tow bar wiring that has a 4-Way flat end. If the coach has a 7-Way round pin connector then you can use an adapter such as # 47405. But you will likely need a 4-Way extension, # HM47115, to reach from the front of the vehicle to the coach. If your coach has a 6-Way round pin connector then you would use an...
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  • Trailer Wiring Harness Recommendation for a 2014 Volkswagen Golf TDI
    The wiring harness you would need for your 2014 Volkswagen Golf TDI would be the Tow Ready wiring harness part # 119250KIT. This is a universal install harness that will require you to tap into the turn signal wiring to install and will require you to run a wire up to the vehicle battery. I attached an install video and a help article that details how to find the best way to route the power wire up to the battery. To access the taillight wiring you will need to remove the interior panels...
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  • Adapter for 7-Way or 6-Way to Plug Into 4-Way on Vehicle Being Flat Towed
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  • Recommended Adapter to Connect 7-Way Round Pin to 4-Flat Connector
    The Tow Ready 7-Pole Round Pin to 4-Flat Adapter # 47405 referenced in your question is designed to adapt a 7-way round pin to a 4-flat connector that you can hookup to a trailer that has a 4-way. If this is what your trailer uses, and your existing 7-Way round has the traditional pins as depicted below, then this will work great. I am not positive how you were connecting the harnesses before, so I can't be sure as to why the brake lights were not working. This adapter will provide an...
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  • Lamp Out Light Comes On in 2014 Audi A6 When Trailer Is Connected and Trailer Lights Flash Quickly
    It sounds to me like you are experiencing the hyperflashing phenomenon that can occur with LED lights. In this case I recommend wiring in load resistors, like part # ALEDRST1B, to the left turn, right turn, and running light circuits of your trailer. My suggestion is to wire these in right behind your taillights. On the left hand side, one for the left turn wire and one for the running light wire. For the right side you would do the same, one for the right turn wire and one for the running...
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  • Flat Towing Wiring Options for 2014 Ford F-150 Platinum
    Strictly speaking, both you and your friend are correct. It just depends on which type of toad wiring harness is used. The link at right will show you all flat-towing wiring kits for the 2014 Ford F-150 Platinum. These include a custom-fit option from Hopkins, part # HM56000. This kit installs without cutting and splicing by plugging in to the F-150 tail lights and includes integrated diodes to prevent feedback. This operates as a combined lighting system.
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  • Light Kit to Flat Tow a 2015 Ford F-150 Behind a Motor Home
    For your 2015 Ford F-150 you can use 4-diode kit # RM-154. This is a more permanent installation that does require tapping into the vehicle wiring. For a more temporary solution you could use a magnetic kit such as # RM-2120 but you would need to also use tow light partners # TLP01 because of the aluminum used in the 2015 Ford F-150s.
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  • Will Hopkins Adapter 7-Way Round Pin To 4-Way Flat # 47405 Fit a 2001 Land Rover Discovery II
    The trailer wiring adapters are not vehicle specific. They are universal and will be matched by what type of connector is on the tow vehicle and what type of connector is on the trailer. The Hopkins Adapter 7-Way Round Pin To 4-Way Flat, part # 47405, is for a vehicle that has a 7-Way round pin connector and you are connecting to a trailer with a 4-Way flat connector. The 7-Way blade style connectors are more common than the 7-Way round pin connectors. I would check the 7-Way connector...
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  • Can Hopkins Smart Hitch Camera be Used With 4-Way?
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  • 7 way Round to 4 Way Flat Adapter Recommendation
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    The diodes in the Roadmaster 6-diode wiring kit # 154-792-118158 will be installed after the converter # 118158 (included in the Roadmaster 6-diode wiring kit) when using this kit. The easiest place to install the diodes is right behind the tail light assemblies where the wiring is easily accessible. I included a couple helpful articles, video review and a picture for you to view.
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  • Wiring US 4-Way Trailer Connector to Trailer with European 7-Way Trailer Wiring
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  • Can a European 7-Way Trailer Connector be Converted to a U.S. 4-Way
    No. The 7-Way end in the # 47405 adapter is made for the North American style of 7-Way round pins. A European 7-Way, see picture, has separate turn signals and brake lights and a circuit for fog lamps. The tail lights are also separate. You would need to fabricate a special adapter to get the 2 to work together. I would need to know which end has the European 7-Way, the vehicle or the trailer. It would also require a semi-permanent change to the connector on the vehicle or possibly the...
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  • Adding 4- to 7-Way Adapters on a 2000 Toyota Tundra and 2013 Toyota Sienna with 4-Ways
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  • Can a 12 Volt Battery on a Dump Trailer be Charged from a 7-Way Trailer Connector
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  • Diode Wiring Kit Recommendation for 2014 Ford F-150 Towed by Motorhome
    I recommend Roadmaster Universal Hy-Power Diode Wiring Kit part # RM-154. This kit is a confirmed fit for your 2014 Ford F-150. It wires diodes into your existing F-150 wiring and will use the factory lights when towing. We have detailed instructions for you to review, see link, and a video installation of this kit also.
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  • Lighting to Tow a 2015 Ford Fiesta ST Behind a Motor Home
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