bing tracking image
  1. Trailer Wiring
  2. Hopkins
  3. Wiring Adapters
  4. Single-Function Adapter
  5. 4 Flat
  6. Plug Only
Adapter 7-Pole Round Pins To 4-Pole Flat

Adapter 7-Pole Round Pins To 4-Pole Flat

Item # 47405
Retail:$17.47
Our Price: $13.53
You Save: 23%
Trailer Wiring
Shipping Weight: 0.33 lbs
Add to cart
In Stock
Hopkins Single-Function Adapter Trailer Wiring - 47405
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

Customer Photos

Videos

Need help with installation?
Locate installers near me
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.
  • All Info
  • Reviews (32)
  • Q & A (0)
  • Videos (1)
  • Photos

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:  4.6 out of 5 stars   (32 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:

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



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:

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?

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:

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:

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 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:

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



by:

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



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:

As advertised and works well



by:



by:

good price.



by:



by:



by:



by:


25
32
Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring

  • Adapter for 7-Way or 6-Way to Plug Into 4-Way on Vehicle Being Flat Towed
    I'm sure we have what you need but I'm not certain exactly what trailer connector you have on your Bobtail truck. It looks like there are a number of potential options for the type of connector you might have, so what I can do is give you the options for an adapter so you can choose the right one. - 6-Way Round: Hopkins Endurance Flex Trailer Connector Adapter - 6-Pole to 4-Pole # HM47320 - 7-Blade: Hopkins Heavy-Duty Trailer Coiled Wire Adapter for 7-Way to 4-Wire Flat # HM47065 - 7-Round:...
    view full answer...
  • 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.
    view full answer...
  • 7-Way Round to 4-Way Flat Connector Recommendation
    We have just what you need. The 7-Way Round Pin to 4-Flat Adapter # 47405 will plug into a 7-way round like you have at the back of your truck and will give you a 4-way flat like you are needing.
    view full answer...
  • Wiring US 4-Pole Trailer Connector to For Trailer with European 7-way
    I am not aware of the existence of an adapter, but one could be easily constructed. You will need to find a vehicle-side socket to receive the plug from your trailer. We do not carry them, so you will need to obtain one locally. You will also need a vehicle to vehicle taillight converter like part # 118158 and a trailer side 4-pole like part # 18004. You would then wire the converter as shown in the diagram I provided. Using this adapter will separate the turn signal back out so that...
    view full answer...
    Image 1 for
  • Solution for Trailer Brake Controller that Activates with Vehicle Hazard Lights
    What you need is the part # 5501. This adapter is designed for your exact application. It will allow your hazards to illuminate and function without activating your brake controller each time the lights come on. I attached a diagram that details how it installs as well.
    view full answer...
    Image 1 for
  • 7-Way to 4-Way Adapter Recommendations
    If you have a blade style 7-way you would need the part # PK12716 to convert it to a 4-way. If instead you have the less common 7-way round you would want the part # 47405.
    view full answer...
  • Converting a Trailer with 12 volt Lights to 24 volt Lights for Compatibility with a Euro Spec Truck
    I think your only real option would be to replace the trailer lights on your trailer with lights that are compatible with 24 volt systems since there isn't an adapter available that we offer that would work for converting your 24 volt system to work with a 12 volt lighting system. Right now, we have a few select 24 volt tail lights. We have # STL23R24B and # STL90R24B. For turn/marker lights we have # STL90A24B and # STL23A24B. And for reverse lights we have # BUL23C24B.
    view full answer...
  • 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...
    view full answer...
  • Flat Towing Wiring Recommendations Using an Opel Corsa to Flat Tow a Mazda Rusler LDV
    Unfortunately we do not have any custom fit wiring for either of the vehicles that you have mentioned. However I have included several helpful links below that detail flat towing wiring options for you. I suggest using the 7-way connector on the vehicle that will be towing the secondary vehicle and using one of the options listed below to activate the signals on the secondary vehicle. If you have the room for installing a bulb and socket kit like the # RM-154 is another option. This kit...
    view full answer...
  • What to Do with 12 Volt Circuit when Adapting US 7-Way Trailer Connector to European 7-Way
    If the European 7-Way trailer connector does not have a 12 volt circuit (which it shouldn't) then you will not have to do anything with that circuit on the vehicle side. When you add a US style 7-Way to the bike rack that circuit will just dead end at the connector. If there is a loose 12 volt circuit wire then you can just use a wire nut or electrical tape and just cap it off and stow it out of the way.
    view full answer...
    Image 1 for
  • Adapter to Go From a 7-Way Socket on 2014 GMC Savana to Trailers with 4- and 5-Way Flat Plugs
    There are 2 types of 7-Way vehicle side sockets, both are round, but the difference is the pins. You likely have a blade style 7-Way connector on your 2014 GMC Savana and for a 4- and 5-Way adapter you can use # A75TB. If your 7-Way has round pins and not blade style pins then we have adapter # 47405 which is a 7-Way round pin to 4-Way adapter. There isn't a 5-Way option if the vehicle has a round pin design. I have included a picture showing the different vehicle side 7-Ways for you.
    view full answer...
    Image 1 for
  • 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.
    view full answer...
  • 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...
    view full answer...
    Image 1 for
  • Converting European 7-Way on 2014 Volkswagen Golf to US Spec 7-Way
    You will need to replace either the connector on the VW or the one on the trailer. It would be easier to change the one on the VW because a US spec trailer has different functions than a European trailer and the functions would not match up. US trailers have combined brake lights and turn signals. A European 7-Way has a separate circuit for each light. Since your Golf already has a trailer connector all you will need to do is cut off the 7-Way end. Then you would use a convert to combine...
    view full answer...
  • Adapter Recommendation to Go From 7-Way Round to 4-Way Flat
    You have a 7-way round connector on your truck so you would instead need the part # 47405 and not the # 47345 that you referenced.
    view full answer...
  • Adapter for 2015 Audi Q5 to go From 7-Way to 4-Way
    The 7-way you have on your trailer is most likely a 7-way blade style connector so you would need the part # 47345. If you happened to have a 7-way round pin connector instead the adapter you would need is the part # 47405. The adapter you referenced is designed for Euro style connectors which wouldn't be what you have.
    view full answer...
  • 2015 Ford Transit T-350 Van Trailer Connector not Working What Should I check
    From what I understand your 2015 Ford Trasit T-350 has a connector on the back for use with trailers that looks similar to the Custer Trailer Connector part # KIT-7P-4 and you have added an adapter similar to 7-Pole Round Pin to 4-Flat Adapter part # 47405 to plug your 4-way flat trailer plug into and you are getting no power to the lights at all. This sounds like a pretty common issue we run into often. That being the ground wire. This could have been damaged or has corroded at the connection...
    view full answer...
  • Adapter Availability for Converting European Trailer Wiring for Use with 4-Pole U.S. Connector
    We do offer a range of wiring adapters for U.S. standard trailer wiring to convert from, for example, 7-way to 4-way, 5-way or 6-way wiring. These various connector types are shown in the linked article on trailer wiring. However, European trailer wiring does not combine multiple functions on one wire like U.S. wiring. U.S. 4-pole trailer connectors combine stop and turn signals on one wire; the yellow wire carries stop and left turn; the green wire carries stop and right turn. Since your...
    view full answer...
  • 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...
  • Availability of 7-Way Round to 4-Way Trailer Wiring Connector
    Since you have a 7-way round connector the correct adapter is the part # 47405 to go from that to a 4-way.
    view full answer...
  • Changing from European 7 Way Plug to US 5 Way Plug on Land Rover D90
    First off, huge LR Defender 90/110 fan here, so congrats on the new Rover; they're the only truck I would trade my Jeep for! Now I'll stop being a fanboy and try to answer your question.... I think in order to preserve some of the integrity of the vehicle (considering how valuable they are in original condition), your best bet is going to be to leave the Euro 7 way plug on the vehicle as is and splice in a separate US style 4/5 way wiring harness to the vehicle. The main issue here,...
    view full answer...
    Image 1 for
  • Are Diodes Needed If Vehicle to Vehicle Tail Light Converter 118158 Is Used to Tow European Trailer
    You will not necessarily need diodes because the back feeding would only be slight and should not be enough to cause any problems. But if you wanted you can still use diodes, # RM-690, one on the right turn/brake and one on the left turn/brake circuits on harness 18252. Basically, they will go before the # 118158 harness on the green and yellow wires.
    view full answer...
  • Can a European 7-Way Trailer Connector be Converted to a U.S. 4-Way
    You have 2 options. First you can convert the Ford Focus wiring harness, after installed, to match the trailer. Or you can convert the trailer connector to match the vehicle connector, once it is installed. The easiest thing to do would be to convert the trailer but there may be certain lights and functions required in Europe that are not required in the U.S. I will try to cover both ways for you but there is no simple adapter for either method. To convert the vehicle, first you will...
    view full answer...
  • 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...


< Previous



Do you have a question about this Trailer Wiring?


Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Michael H
Expert Research:
Michael H
Employee Jeff D
Expert Research:
Jeff D
Employee Jameson C
Expert Research:
Jameson C
Employee Dustin K
Video by:
Dustin K
Employee Cole B
Installed by:
Cole B
Employee David F
Installed by:
David F
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Updated by:
Alexander C

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.