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Adapter 7-Pole Round Pins To 4-Pole Flat

Adapter 7-Pole Round Pins To 4-Pole Flat

Item # 47405
Our Price: $10.63
Trailer Wiring
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Shipping Weight: 0.31 lbs
In Stock
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 or call 1-800-940-8924 for expert service.
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  • Reviews (23)
  • Q & A (0)
  • Videos (1)
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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 Hopkins Wiring - Wiring Adapters - 47405 Review

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:  4.7 out of 5 stars   (23 Customer Reviews)


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 and sure enough it was available. I made the purchase, arrived in a couple days and made a perfect fit.


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?

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.
-- Etrailer Expert Katrina B - 04/20/2022


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


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!! Best company I've EVER done business with.


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


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!


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.


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


Good product, good people


Great product and price


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


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




Good plug came quick and pic is great


As advertised and works well



good price.





See what our Experts say about this Hopkins Trailer Wiring

  • Wiring Adapter for Kabota Tractor To Use Standard 4-Way Trailer Connector
    Yes, the Adapter 7-Pole Round Pins To 4-Pole Flat part # 47405 will work on your Kabota Tractor. The tractor has what is called an agricultural 7-pole which is pretty common. I know it is hard to tell from the photos but the ground terminal on the above is larger than the rest and will match up to that on your tractor so you should not have any fit concerns. This adapter will then let you power a trailer with standard 4-flat.
    view full answer...
  • Are there Different Kinds of 7-Way Trailer Connectors that Could be on a 1984 Chevy/GMC Suburban
    There are different types of 7-Way trailer connectors. But the 2 that you will find most on a vehicle are the round pin style or the blade style. The more common one on a vehicle with a factory 7-Way is a blade style. Adapter # 47405 is for round pins If the 7-Way on your 1984 Suburban looks like the one in the picture then you can use adapter # 47405. If the 7-Way on your vehicle has flat blades and not round pins then you would need a different adapter, # PK12716.
    view full answer...
    Image 1 for
  • 7-Way to 4-Pole Adapter Not Functioning When Installed on 2001 Land Rover Discovery II
    I'd begin by testing the 7-way on the Land Rover. The trailer wiring FAQ I've linked you to will show you which pins on the 7-way will show voltage as each turn signal/brake lamp/ running lamp function is activated. Make sure the 7-way is wired as shown in the FAQ. Then, plug the adapter into the 7-way and test each function. If you don't have a circuit tester, we offer one as part # PTW2993. Usually when you have both turn signals operating at the same time, it indicates a ground problem....
    view full answer...
  • 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...
    view full answer...
    Image 1 for Image 2 for
  • Does 7-Pole to 4-Way Trailer Adapter Have Converter Built In?
    The Adapter 7-Pole Round Pins To 4-Pole Flat # 47405 will not have the converter built in to combine your separated turn signals and stop light. That adapter will require a separate converter. For an option with the built in converter use the Pollak 7 Pole Round Pin to 4 Pole Flat Wiring Adapter # PK12742.
    view full answer...
  • 7 way Round to 4 Way Flat Adapter Recommendation
    The 7-way round style of connector that the # 47405 has is the same style that is typically found on tractor trailer type rigs. The issue you may run into is that the taillight circuits of your tractor are separate, meaning that the brake lights and the stop lights are carried on separate circuits. If that is the case just the # 47405 wouldn't work. If this is the case you will want the converter part # 119130 and a male round 7-way part # PK11700.
    view full answer...
    Image 1 for

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