bing tracking image
  1. Trailer Wiring
  2. Hopkins
  3. Wiring Adapters
  4. Single-Function Adapter
  5. 7 Round - Blade
  6. Plug and Lead
Hopkins Trailer Connector Adapter - 7-Pole Round Pin to 7-Pole RV

Hopkins Trailer Connector Adapter - 7-Pole Round Pin to 7-Pole RV

Item # HM47425
Our Price: $28.45
You Save: 34%
Trailer Wiring
Shipping Weight: 0.81 lbs
Add to cart
In Stock
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


Need help with installation?
Locate installers near me
This adapter plugs quickly and easily into your 7-way, round-pin, vehicle-end connector to convert it for use with a 7-way, blade-style, trailer-end connector. Flexible wire between plugs provides a wide range of motion to ease installation. Great Prices for the best trailer wiring from Hopkins. Hopkins Trailer Connector Adapter - 7-Pole Round Pin to 7-Pole RV part number HM47425 can be ordered online at or call 1-800-940-8924 for expert service.
  • All Info
  • Reviews (54)
  • Q & A (0)
  • Photos

Hopkins Trailer Wiring - HM47425

  • Wiring Adapters
  • Single-Function Adapter
  • 7 Round - Blade
  • Plug and Lead
  • 7 Round - Round
  • Hopkins

This adapter plugs quickly and easily into your 7-way, round-pin, vehicle-end connector to convert it for use with a 7-way, blade-style, trailer-end connector. Flexible wire between plugs provides a wide range of motion to ease installation.


  • Adapter converts your 7-pole, round-pin, vehicle-end connector to a 7-pole, RV-style connector
  • Flexible wire between plugs provides extra reach and wide range of motion
    • Increases installation options
  • Convoluted tubing (wire loom) protects wires from the elements
  • Easy-grip design makes installing and removing the 7-pole, round-pin plug effortless
  • Built-in cover and mounting bracket included on 7-way RV plug
  • 90-Day limited warranty

This adapter allows the 7-Way, round-pin, vehicle-end connector to work with 7-way, RV-style, trailer-end connector on the right.

7-Way, Round-Pin, Vehicle-End Connector7-Way, RV-Style, Trailer-End Connector

47425 Hopkins Trailer Connector Adapter - 7-Pole Round Pin to 7-Pole RV

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Hopkins Trailer Connector Adapter - 7-Pole Round Pin to 7-Pole RV - HM47425

Average Customer Rating:  4.7 out of 5 stars   (54 Customer Reviews)

This adapter plugs quickly and easily into your 7-way, round-pin, vehicle-end connector to convert it for use with a 7-way, blade-style, trailer-end connector. Flexible wire between plugs provides a wide range of motion to ease installation.


Brake doesn't work locks them up

Etrailer Expert

Katrina D.


It seems that they are locking up because your set up will require part # 119130 and part # etbc7. As per one of our installers, semi's have a separate stop turn circuit because their trailers have air brakes. You will not be able to use that adapter with your semi harness. Your semi harness does not have a wire to carry electric brakes.


Product won't work correctly. I've tried it with 2 different trucks and 3 different trailers. Each Turn signal will active the hazard lights, and no tail lights. When pressing brake lights, all side marker lights will light up.

Etrailer Expert

Sierra K.


It sounds like something is not wired right in the plug. This item has a 90 day warranty so I will have Customer Service reach out to you. Attached is a help article that explains which color wire each function should handle:


Well made is all I can say about this adapter only because I used it once it worked out great but have not had a need to use it again. I keep it with my other towing plug adapters as I'm sure I will need to use it again someday!

Rod H.


After a year of using the adapter plug it has worked flawlessly Everytime Never had any issues with it not working the way it was supposed to Im very satisfied with this product and would recommend it to others


I will order all my trailer needs from from now one. It was excellent being able to order what I needed and cheaper than the auto parts store.


Excellent product and A-1 shipping. Great response from company on shipping time


Hey just what I needed in a pinch to hook my gooseneck to my semi to tow my regular truck and got it to me just when I needed it thank you


The wiring plug in for my tractor to trailer works great! Etrailer did a great job helping me pick the correct wiring plug!

Tim M.


It is still working well after 1 year!


Adapter is just what I need to connect my gooseneck trailer (12V) to my military M931 tractor (24V) that has a step down converter box to accommodate the military 24V cable to the usual 12V tractor cable - this then allows the gooseneck connector to function. Appears to be well made and fits perfectly on both ends. It was shipped promptly. In fact, locating the NUMBER to search for the adapter was the hardest part - once I had that going to etrailer and putting in the number it popped right up, and the pictures helped assure me it was correct for my application. My other option of 24V magnetic lights on the trailer has been retired!


I thought I would need this more than I do but I haven't towed the trailer with the tractor where I needed lights or turn signals. Works well, actually better than the tractor, half the lights don't work. (Electrics by Lucas, prince of darkness)


I looked all over for this adapter at seven stores and everyone told me that they don't make this adapter, I have to change my trailer plug.
I looked it up on the net and you have it and I ordered it and had it in three days and it is just what I needed.
They do make it, but venders don't want to stock it. after I received it I found one at NAPA for ten dollars more then I paid for it here,
Thank you,


Used this to hook up from a box truck rigged with a 7 round pin to 7 blade on a cargo trailer. Everything fit great and worked correctly. No issues with the electric brakes.


I ordered the wrong wiring harness and was given a return slip for credit once I realized my mistake. I was sent the correct one immediately and it fits perfectly. Great service and very reasonable costs. Thank You!


We have an 2000 Newell Coach with the round 7 pin receptacle
With this adapter all of our other adapters will fit our trucks, trailers, as well as the Newell.
Thanks for the quick shipping and great product

Ricky Z


Wanted to be able to use the lights on a 30' flatdeck with my tractor for hauling round bales. This adapter works great. Photo attachment didn't work, but the 7 round-pin on my JD 7200R to the 7 flat pin on my trailer worked. Seems well made.


I have ordered from e trailer several times. Now that I have 4 trailers I will probably be ordering more parts. They ship quickly and send you updates on you order. the products are top quality. Thanks etrailer.


Worked great for my needs. I only needed the round 7-pin end so I cut off the 7-blade end and wired it for my need.


The trailer adapter is exactly what I needed. Thanks for all the help


fits between the tractor and trailer


Works well, converting from one type plug to the other in our fleet saves time from having to rewire all trucks/trailers


Perfect.... Exactly what I needed to hook up my fifth wheel camper to semi!!! Thanks


They look good havent used them yet


Extremely fast shipping and the item is heavy duty and was exactly what I was looking for. thank you so much for great cheap fast shipping


Product was exactly what I needed!! Great plug in no re wireing needed thanks!!


Works great

Robert R.


Best ever


Product arrived as expected and is the correct part as needed. The additional pictures of the product helped identify this part would fit my requirements.

Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring

  • Wiring for 7-Pin Round to 7-Blade Adapter
    There is not a wiring diagram for the Hopkins Trailer Connector Adapter - 7-Pole Round Pin to 7-Pole RV # HM47425 but I have added a photo showing the functions of a 7-pin round and 7-way RV blade style, which is what this adapter was intended for. The wires will match the functions shown without any type of re-wiring needed. The only thing you need to be sure of is that you have the same 7-way connectors, and if you do it is assured this adapter will work. I have added a link to a video...
    view full answer...
    Image 1 for
  • Brake Controller Does Not Work when Using 7-Pole Round to 7-Pole Blade Adapter
    It does sound like something is mismatched in the wiring. Either the truck or the trailer would appear to not be following the standard pin out. On the output side of adapter # HM47425 the brake pin is in the 5 oclock position if looking at the pins. If looking at the back of it where the wires attach it would be in the 7 oclock position. I have included a link to a help article that shows how different trailer connectors are normally pinned out so you can compare them with what you have...
    view full answer...
    Image 1 for
  • Adapter to Connect a Round 7-Way Trailer Connector on a Semi to a Gooseneck Trailer with a 7-Blade
    Use Hopkins part # HM47425. It's an adapter that plugs in to your round 7-way and gives you a 7-blade RV style connector.
    view full answer...
  • Trailer Connector Adapter for 7-way Round Pin to 7-way Blade Connector on Dump Trailer
    The Hopkins Trailer Connector Adapter you've looked at, part # HM47425 will adapt the existing 7-way round pin the tow vehicle to the 7-way RV blade style connector on your dump trailer. You can see a product demonstration video by clicking the provided link.
    view full answer...
  • 7-Pole Agricultural to 7-Blade RV Trailer Connector Adapter
    Yes, the male 7-pole connector on the Hopkins Trailer Connector Adapter part # HM47425 is commonly found in agricultural applications. The female version of this connector is likely what is on your tractor now. This adapter will allow you to pull your utility trailer with your tractor assuming both the vehicle side and trailer side connectors match the attached photo. I have also attached a review video of the adapter for you as well.
    view full answer...
    Image 1 for
  • 7-Pin to 7-Blade Trailer Adapter Pin and Blade Function Locations
    The Hopkins Trailer Connector Adapter - 7-Pole Round Pin to 7-Pole RV # HM47425 adapts the pins from the Peterbuilt wiring to the traditional trailers for cargo and camping. I've attached a photo as well as an article to help with the wiring locations and functions.
    view full answer...
    Image 1 for
  • Hopkins 7-Round to 7-Blade Adapter Pins
    Appreciate the photo of your 7-round connector and I have added a diagram showing the pin differences from a 7-way round like yours to a 7-blade, which is what the pins will be for the Hopkins Trailer Connector Adapter - 7-Pole Round Pin to 7-Pole RV # HM47425. To use a trailer brake controller you can change out to a standard 7-way since there isn't a brake controller wire option on your current 7-way; you can re-wire it with the Hopkins Endurance Quick-Install 7-Way Trailer Connector...
    view full answer...
    Image 1 for Image 2 for
  • Adapter Recommendation for Going from 7-Way Round to Flat
    There is no taillight converter installed in the Adapter part # HM47425 that you referenced so if you need to go from separate to combined lights then this kit is not for you. You will need to add a converter, like the Tow Ready, # 119130. Just cut off the 4 way end and wire it into this adapter. I have attached a picture which illustrates this.
    view full answer...
    Image 1 for
  • 7-Way Blade to 7-Way Round Adapter Recommendation
    It sounds like you need a 7-way adapter. If the pins on the 7-way of your truck are blades and the pins on your trailer are round pins then you would need the # 47595. If the setup is the opposite of that you would need the part # HM47425 that you referenced.
    view full answer...
  • Can Hopkins Adapter be Used to Connect Bargman 7-Way on Truck to 4-Way on Trailer
    Yes, a 7-Way to 4-Way adapter like the Hopkins # 47345 is exactly what you need to connect the Bargman 7-Way on your truck to the 4-Way flat on the trailer. This will plug right into the truck's 7-Way to provide you with a 4-Way at the other end. No other wiring will be needed. We do not have the particular Hopkins model adapter that you mentioned available but this upgraded version actually features an integrated tester as well so you can quickly see if there are any issues with the...
    view full answer...
  • Recommended Adapter to Convert a 7-Round to a 7-Flat Trailer Connector
    We have you covered. Using the Hopkins Trailer Connector Adapter part # HM47425 will allow you to plug into your 7-Round then plug the goosenecks directly into it. This will convert the signals and give you the appropriate wiring needed. Check out the video I linked for you on the adapter.
    view full answer...
  • Troubleshooting No Trailer Power or Running Lights with Hopkins 7 Round to 7 Blade RV Adapter
    It sound like some of the functions on your trailer wiring are not connected in the standard pin locations which is what both Pollak and Hopkins use. On your trailer, locate the wires and pin location by function only as color coding is not standard across all manufacturers. Start by testing the 11:00 and 1:00 pin positions on your trailer with a circuit tester like # PTW2979; this is most likely where your wires are crossed. There could also be a short between these two circuits since...
    view full answer...
    Image 1 for
  • Determining Functions of Trailer Wiring 2020-21 Kenworth T270
    Most likely the wiring color codes of your Kenworth are not standard so what you'd need to do is use a circuit tester like the # PTW2992 to determine what they are and wire by function instead.
    view full answer...
  • Using an Adapter to Connect a 7-Round to a 7-Flat RV Connector
    Sounds like the adapter you have is not the correct adapter for the OEM truck plug. The 7-round to 7-flat trailer wiring adapters, like the Hopkins # HM47425, are wired to convert the typical 7-round wiring to the RV style 7-way with the flat pins. If your trucks plug wiring configuration is not wired like the standard 7-round, then when hooking the adapter up to your RV plug will cause the type of malfunction that that you are seeing. I have attached a picture that shows what the commercial/agricultural...
    view full answer...
  • How To Connector 7-way Round Trailer Connector To 7-way Blade Connector When Adapters Aren't Working
    Since you have issues with two different adapters, it is likely that the wiring for your trailer is not matching the way the 7-way blade connector on your 2007 Ford F-750 is wired. To keep from having more issues your best bet is to replace the 7-way round connector on your trailer with the Pollak Black Plastic, 7-Pole, RV-Style Trailer Connector - Trailer End # PK12706 eliminating the need for an adapter. You will need to test the functions of each wire going to the 7-round connector...
    view full answer...
    Image 1 for
  • Can the Hopkins # HM47425 and Bargman # 50-67-210 be Used to Replace Adapter Cable
    Although we do not carry that exact cable, as you mentioned, the parts that you mentioned would be a great way to replace your cable. The Hopkins Trailer Connector Adapter # HM47425 would change the 7-Way round connection on your truck to a 7-Way blade style. You can then use the Bargman 7-Way Molded Trailer Wire Connector # 50-67-210 to connect the Hopkins adapter to your trailer. Since both ends will be the female, or plug, ends then this combination will work.
    view full answer...
    Image 1 for
  • How to Adapt 7-way Round Pin Trailer Connector on Kenworth Tractor to RV Blade Style 7-Way
    There isn't an off-the-shelf adapter that'll do exactly what you're wanting to do, but you can certainly piece one together. Your best bet would be to install a taillight converter and a 7-way RV blade-style trailer connector on the Kenworth tractor. This way, you'd have 2 functioning trailer connectors. I'd recommend using the # 119250KIT taillight converter which would tap into the circuits feeding your tractor trailer 7-pin round plug. The yellow wire taps into the feed for the left...
    view full answer...
  • Are Hopkins and Pollak 7-Way Round Pin to 7-Way Blade Trailer Connector Adapters the Same
    Hopkins Trailer Connector Adapter # HM47425 and Pollak Trailer Connector Adapter # PK12-724 are both 7-Way round pin to 7-Way blade style adapters. Both plug into a tow vehicle that has a 7-Way round pin connector so you can tow a trailer that has a 7-Way blade style connector. They are just from different manufacturers.
    view full answer...
  • Comparing Pollak and Hopkins 7-Way Round Pin to 7-Way Blade Style Adapters
    Both adapter # PK12-724 and # HM47425 plug into a 7-Way with round pins and provide a 7-Way blade style connector. They are made by different manufacturers but accomplish the same task. Pollak adapter # PK12-724 has a 1 year warranty whereas Hopkins adapter # HM47425 has a 90 day warranty.
    view full answer...
  • Adapter for Vehicle 7 Blade Connector to Trailer 7 Round Connector
    We have exactly what you need for an adapter to go from the 7-blade connector on your vehicle to the 7-round connector on your trailer: - Pollak Trailer Connector Adapter - 7-Blade Plug to 7-Pole Round Pin - Nylon # PK12727 or - Pollak Trailer Connector Adapter - 7-Blade Plug to 7-Pole Round Pin - Die-Cast Zinc # PK12728 The only difference between the two is that one has a nylon construction on the plug and the other is a die-cast zinc. I have added links to video reviews of both adapters...
    view full answer...
  • How To Install a 7-Way Trailer Connector and Brake Controller On a Freightliner Rollback M2
    I do have an option for you but there aren't any direct wiring adapters to go from a 4-round to a 7-blade. Therefore, you'll need to remove the 4-round and install a 7-blade which is really your best option since this is far more common for trailers. In order to do this you'll need Hopkins Endurance Quick-Install 7-Way Trailer Connector part # HM47210. This will replace the 4-round and you can attach the wires from the 4-round to this(green, yellow, brown, white). It may not be color for...
    view full answer...
    Image 1 for Image 2 for Image 3 for Image 4 for
  • Wiring Adapter for a 1997 Land Rover Discovery with 7-Way Round Pins
    Trailer Connector Adapter # 118710 is an odd duck but not as odd as what you have on your 1997 Land Rover Discovery! Actually, it isn't that odd. It is a 7-Way round pin, but I wasn't expecting it to be on that particular vehicle. The design of it though is unique. First, make sure it is active by testing those pins using a circuit tester such as # PTW2993 or a meter if you have one. If you have power with the various vehicle lights on, then you will need adapter # PK12742 to go from a...
    view full answer...
    Image 1 for
  • 7-Way Round Pin to 7-Way Flat Blade Adapter W/Compatible Brake Controller To Control Trailer Brakes
    As your 7-Way pin connector uses separate turn signals and brake light wiring you will need the to create a custom harness to be able to have everything function properly including the electric brakes. First you will start with the Pollak Heavy-Duty, 7-Pole, Round Pin, Trailer Wiring Connector # PK11700 to connect to your vehicle. You will be able to connect the Hopkins Tail Light Converter # HM48847 and Hopkins Endurance Quick-Install 7-Way Trailer Connector # HM47210 to the appropriate...
    view full answer...
    Image 1 for Image 2 for
  • Solution for Freightliner to Tow Trailer with 7-Way Blade Connector
    Our 7-way round to 7-way blade adapters do not have a signal converter built into them so you'd have to use a converter box like the # RM-732 to get the signal combined like your trailers need. Now what I would recommend is install a 7-way blade on your Freightliner with the harness part # PK11998 and the socket part # PK11893 ran to your current wiring but installing the # RM-732 between the new and old 7-way.
    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 Jameson C
Expert Research:
Jameson C
Employee Tyler C
Written by:
Tyler C
Employee Kathleen M
Installed by:
Kathleen M
Employee Alexander C
Updated by:
Alexander C

At 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.

Product Experts Available Now!
Call 1-800-940-8924