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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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$13.27
Retail:$17.84
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Trailer Wiring
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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:

Plug and play for my project. LOL



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:

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?

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 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 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:

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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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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  • 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:...
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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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  • 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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  • 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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  • 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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  • After Installing Tow Bar Wiring Harness HM56000 on 2008 Ford Edge Brake Lights Do Not Work
    You will want to unplug the 2008 Ford Edge from the motor home and use a circuit tester, such as # PTW2993 if you don't have one, to test the motor home side trailer connector. First test it without the adapter plugged into the 7-Way. Have someone sit in the motor home and go through the light functions while you test with the circuit tester. If the brake light signal is not coming through, then there is likely a blown tow package wiring fuse or wiring issue on the motor home you will...
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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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  • Best Location to Wire a Tail Light Isolating Diode System
    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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  • 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 # C56175 and a male round 7-way part # PK11700.
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  • 7-Way to 4-Way Adapter for a 1998 Ford F-150
    What you have there on your 1998 Ford F-150 is a 7-Way blade style connector, not a round pin connector. So for an adapter to use trailers that have 4-Way flat connectors I recommend # PK12716. I have linked a video review of this adapter for you.
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  • Wiring US 4-Way Trailer Connector to Trailer with European 7-Way Trailer Wiring
    Since you want to go from a 4-way on your vehicle to a trailer with a European 7 flat, you will simply be able to use the Tow Ready Vehicle to Vehicle Tail Light Converter # 118158 (this doesn't work with LED lights). This will take the combined stop and turn signal wires on your 4-way and separate them for your European 7-way. You will connect the 4-way color-for-color and the running light will run around this adapter versus through it, and the ground will need to be spliced so it can...
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  • 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,...
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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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  • Can Hopkins Smart Hitch Camera be Used With 4-Way?
    You would not be able to use the 7-Pole Round Pin to 4-Flat Adapter # 47405 to install the Hopkins Smart Hitch Backup Camera and Hitch Aligner System # HM50002. This camera and aligner require a vehicle to have either a factory tow package or to be hardwired into the vehicle. I've added a link to the installation instructions for you to take a look at as well as a link to a video review of this system.
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  • 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.
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  • Parts Needed To Install A Cargo Carrier Light Kit That Plugs Into A 7 Way Round Connector
    What you're going to need is a light kit like # 20174, and a 4 pole to 7 way round adapter # 47405. Simply plug the 4 pole trailer connector from the lights into the adapter, and then plug the adapter into your 7 way round connector on your 2006 Chevrolet Express. The harness on the light kit # 20174 is 6' long, and the off-set Y-harness is 3' long, which should be plenty long for you.
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  • 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.
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  • 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.
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  • Can a 12 Volt Battery on a Dump Trailer be Charged from a 7-Way Trailer Connector
    The 12 volt circuit on most 7-Way trailer connectors is fused at 30 amps/12 volts. At best it can provide a maintenance charge to a trailer mounted battery. But it cannot charge up a battery; at least not one that is the size of the battery used to operate functions on a dump trailer. Most vehicle alternators are not strong enough and the tow package wiring not large enough for enough amperage to get back to the battery. I recommend using an AC charger when you can to charge and recondition...
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Info for this part was:

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