bing tracking image
  1. Trailer Wiring
  2. Hopkins
  3. Wiring Adapters
  4. Multi-Function Adapter
  5. 4 Flat
  6. 7 Round - Blade
Adapter 4-Pole to 7-Pole and 4-Pole
Hopkins

Adapter 4-Pole to 7-Pole and 4-Pole

Part Number: 37185
In Stock
$55.77
Retail:$60.93
You Save: 8%
Trailer Wiring
Add to cart
Hopkins Wiring Adapters - 37185
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

In Use/Installed

Customer Photos

Need help with installation?
Locate installers near me
Adapter converts from 4 pole wiring on vehicle to 7-pole round plug and 4-pole flat. Additional wire leads for brake, power and accessory. Great Prices for the best trailer wiring from Hopkins. Adapter 4-Pole to 7-Pole and 4-Pole part number 37185 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
  • All Info
  • Reviews (634)
  • Q & A (0)
  • Photos

Hopkins Trailer Wiring - 37185

  • Wiring Adapters
  • Multi-Function Adapter
  • 4 Flat
  • 7 Round - Blade
  • Plug and Lead
  • 4 Flat
  • Hopkins

Adapter converts from 4 pole wiring on vehicle to 7-pole round plug and 4-pole flat. Additional wire leads for brake, power and accessory.


Features:

  • Adapter converts from 4-pole wiring on your vehicle to 7-pole round plug and 4-pole flat wiring for trailer side
  • Adds additional wire leads for brakes, power, and accessory wiring
  • Wire functions:
    • White - ground
    • Blue - brake
    • Black - hot lead - 12 volt power supply
    • Purple - auxiliary
  • Mounting bracket included


Specs:

  • Connector measures 3" x 3"
  • Distance between vehicle mounting holes: 2-3/16"
  • 90-Day limited warranty


product detail

Wire Functions:
White: Ground
Blue: Brake
Black: "Hot" Lead - 12V power supply
Purple: Aux. - Reverse Lights etc.





Note: If you run the hot lead (black wire), you will need a circuit breaker, for example 9510 (sold separately), between the adapter and the battery itself.



47185B Adapter 4-Pole to 7-Pole and 4-Pole - Hopkins # 47185B, TAP # 37185




California residents: click here


Customer Satisfaction Score:


Customer Reviews

Adapter 4-Pole to 7-Pole and 4-Pole - 37185

Average Customer Rating:  4.8 out of 5 stars   (634 Customer Reviews)

Adapter converts from 4 pole wiring on vehicle to 7-pole round plug and 4-pole flat. Additional wire leads for brake, power and accessory.

by:

Very happy with the 4-pole to 7-pole adapter the etrailer video was a big help.



by:

Really nice trailer wiring adapter. Very easy install. Takes about 30 minutes with all the tools needed. Drill, 7/64 bit for pilot holes to mount the bracket, flat blade screwdriver and 11/32 nut driver and two #10 self tapping metal screws with locking split washers and a couple zip ties to tidy up the wiring harness.



by:

This Brake Controller works great ! With a little pre planning and watching some videos I was able to install this on my ‘99 Ford Expedition. No knee banging or awkward reaching to set the controller the dial is right on the dash panel. Training and dialing the unit in was a breeze and it gives me consistent braking as needed.



by:

Installed on our 2019 Edge ST with no significant issues. Works as expected, has reasonable required depth behind connector for ease of install, and the bracket was quite adaptable after some bending and cutting. Not impressed with the overall feel, though - plastic seems lightweight and cover hinge pin is already rusting after two winter weeks in western PA. Long term durability tbd.



by:

I looked at so many options before deciding on the B&W hitch, but I have no regrets buying it. There is nothing that my car is suitable for towing that this thing can’t accommodate. I even use it on the front hitch of my mower to move trailers around the yard! Adjusts very easily and stows nicely (though on my Ford Edge it rides lower than I like when stowed).



by:

This is a great adapter to retro fit connections on my 2011 Expedition. Simple to instal and great support from etrailer.com.



by:

The product itself is very well made. The 4-pin connector is molded into the product and very sturdy. The 7-pin connector is held closed by a spring and has a foam gasket to keep water out. The 4-pin wiring is only about a foot long, and the additional 7-pin wiring is a bit longer. I do not have a brake controller (but do borrow a trailer with the 7-pin wiring), so I removed those wires. I also hard-wired all the connections, so I can't speak to the quality of the 4-pin vehicle connector.

The mounting bracket is thin steel, which worked well for me, as I had to bend the mounting plate to make it work for my installation. The paint on the mounting plate appears to be high quality as I bent the plate and banged it around quite a bit during install and did not nick the paint. The plate is drilled so that is can be mounted with the 7-pin hinge facing up, down, left or right.

The hardware is zinc coated, so it should hold up well to the weather. I went ahead and replaced it with SS to make sure. I also replaced the standard nuts with SS nylon lock nuts to make sure nothing would back out due to vibration. If you plan on using the supplied hardware, I would strongly suggest Loctite on the mounting nuts.

I installed this on a CX-5 with hitch # 87623, wiring adapter # C56011 and hitch cover # I-728. Over all a very clean installation. The connector is completely hidden inside the bumper, but easily accessible.



by:

This was exactly what I was looking for to add to my 2017 Ford Expedition! It is an easy to install plug-n-play product to convert a factory 4-pin connector to a 4/7-pin connector.

I plugged the 4-pin in, connected the brake wire, and grounded it. Ignoring the auxiliary + power cables, everything worked on the first test. The 4-pin connection was given some dielectric and wrapped with electrical tape to keep it sealed from the elements, and the slack was zip tied to secure it.

I still need to give it some finishing touches (fill the bracket gap with some black silicone, maybe find the reverse and/or power lines), but it lets me haul my camper!



by:

Simple install and it has both the 7 way and the 4 flat plugs.



by:

2018 wrangler unlimited Sport S. Without trailer wiring. Completed installation today. Used a 4 flat along with a 7 pin converter. Works and fit perfectly. Very hot day and work slowly and carefully. Very satisfied . Great folks at etrailer. Great products, great quality and prices. I'm a several time repeat customer and couldn't be more satisfied.
4 pin harness Was a 56407 and the 7 pin adapter was a 37185.



by:

I recently installed the 4-pole to 7-pole adapter on my 2015 Highlander. My first install worked OK, but I ran into a ground clearance issue using the original mounting location. Etrailer suggested using a 2 1/2" mounting box to relocated the connector. Part number 18156 worked perfectly.



by:

The trailer wiring adapter was perfect and shipped in no time. Looks great on my ford ranger. Im very happy.
Was 4 flat only and now I can light my 7 way 18' trailer and have the capacity to add a brake controller (which I will add)



by:

It was great. The instructions were not for my specific year of transit but gave me enough idea to get it done



by:

Exactly what I ordered. Easy installation. Great product.



by:

I bought this so I can convert my dad's trailer to pull I only had a four and I needed a seven so I went and used a four to make it a seven. It's a very nice product it's got nice rubber grommets to keep everything protected.



by:

Works great



by:

Installed on a 2010 Ridgeline. Just what I needed at a great price. Install was a breeze. etrailer is the best place to find all the stuff that auto dealers rip you for. Good quality and the customer service is above reproach.



by:

Just what I need to tow an RV trailer. Also has a four flat connector. Very easy to install on the 18136 bracket.



by:

Easy installation, does exactly what it is intended to do.



by:

Just what I needed!



by:

I use these adapters to install 7-way connectors on trucks that have no factory trailer wiring provisions.



by:

2012 Chevrolet Express..Looks and works great! Easy install..2 1/8" hole saw for center, 3/16" drill bit for mounting screws. Thank you etrailer!



by:

Nice quality adapter harness. I would highly recommend etrailer.com



by:

Wow after Charles great advice this was so simple to install, [online] video was point on and the hardest thing was finding the reverse wire.
Thanks so much for a good product and excellent advice, here is the pic after install!



by:

Hooked up easily, no problems. Works gr eat.


25
634
Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring

  • Parts Needed to Install 7-Way on 2016 Sprinter that Bypasses OEM Wiring
    We can definitely help Wayne but you'll need to first install a 4-way like with the Curt part # C59236 which is a universal style 4-way that fits your Sprinter. To then convert to a 7-way you'd just need the part # 37185 if all you need is trailer lighting. If you have trailer brakes as well you'd instead of the 37185 need the part # ETBC7 and a brake controller like our very popular P2 part # 90885 and you'd be set.
    view full answer...
  • Parts Needed to Install 7-Way on 2020 Honda HR-V with 4-Way
    Hey Michael, if the trailer doesn't have brakes that you need to operate all you need is the part # 37185 to convert your 4-way to a 7-way. If you do need to operate brakes you'd instead need the part # ETBC7 with a brake controller like the P3 part # 90195 and you'd be set.
    view full answer...
  • Parts Needed to Install 7-Way on 2022 Mazda CX-9
    To install a 7-way on your 2022 Mazda CX-9 you would first need to start with a 4-way like the Curt # C56338 which is a custom fit kit that doesn't require splicing. If the 7-way only needs to support trailer lighting function (not brakes) then all you need to convert it to a 7-way is the part # 37185 which plugs right into the Curt 4-way and is ready to go. If you need to operate trailer brakes the 7-way adapter you'd need instead is the # ETBC7 and a brake controller like the Tow Pro...
    view full answer...
  • Parts Needed to Install 4-Way and 7-Way on 2015 Ram ProMaster 1500
    To install both a 4-way and a 7-way on your 2015 Ram ProMaster 1500 you would need to first start with a 4-way kit like the Curt # C58DR and then convert it to a 7-way with the part # 37185 which also has a 4-way on the side of it just like you are wanting.
    view full answer...
  • Parts Needed to Add 4-Way and 7-Way to 2008 Chevy Express Van 3500
    We have just what you would need to add both a 4-way and 7-way to your 2008 Chevy Express 3500. The first thing you need is a custom fit 4-way harness with the Curt # 55540 which you will then convert to a 7-way with the part # 37185. This adapter has both a 4-way and a 7-way on it so there would be no need to unplug it to use a 4-way. If the trailer doesn't have brakes this would as far as you would need to go. If the trailer does have brakes you would need to go a slightly different...
    view full answer...
  • 7-Way Trailer Wiring Recommendation for 2015 Mazda CX-5
    We have a way you can install a 7-way on your 2015 Mazda CX-5 but not all vehicles have custom fit 7-ways made for them so you'd have to start with the more common 4-way like the part # C56011 which is custom fit for your vehicle. From there you'd need to convert it to a 7-way like what your trailer needs. If the trailer does not have brakes all you need is the # 37185 which plugs right into the 4-way and you'd be set. If the trailer does have brakes you'd instead need the # ETBC7 which...
    view full answer...
  • Solution to Install 7-Way and 4-Way on 2002 Toyota Tundra
    The only trailer wiring options we have for your 2002 Toyota Tundra is 4-ways like the part # 118378 which you could convert with a 7-way adapter like the part # 37185 which also happens to have a 4-way on the side of it like you wanted.
    view full answer...
  • Bracket to Mount 7-Way on 2023 Hyundai Palisade
    You'd want a 7-way bracket like the part # 18138 to attach a 7-way to the rear bumper edge of your 2023 Hyundai Palisade. Now to install a 7-way you would need to start with a 4-way like the part # C43FV and then convert it to a 7-way with the part # 37185. This comes with a bracket though so if you go this route you would not need a bracket.
    view full answer...
  • Parts Needed to Install Curt Venturer Trailer Brake Controller C74VV in 1995 Ford F-150
    We can help you with installing a trailer brake controller like the Curt Venturer time-delay controller # C74VV in your 1995 Ford F-150 to operate the brakes on your Hornet trailer. The parts you need depend on how the truck is equipped. If the truck has a factory 4-pole trailer connector you will use harness # C51322 to connect the controller and part # 37185 to provide the 7-way. If the truck has a factory 7-way then all you need is the controller and the harness # C51322. If the truck...
    view full answer...
  • 2022 Nissan Pathfinder Hitch and Trailer Wiring for 7-Way
    The Draw Tite hitch part # DT67GR is a confirmed fit for your 2022 Nissan Pathfinder and then for trailer wiring you'd want the Tekonsha part # TK58VR for a 4-way and then to convert to a 7-way you'd want the part # 37185 if the trailer does not have brakes or the part # ETBC7 if it does. Then you'd also need a brake controller like the Brake EVN # TK63VR and you'd be set.
    view full answer...
  • Trailer Wiring Kit for 1972 GMC Suburban that Draws Power From Battery
    You'd need a 4-way kit like the part # C59496 which uses your current taillight circuits as signal wires and then draws it's power from the battery. Then for a way to convert to a 7-way you'd want the part # 37185 and you'd be set.
    view full answer...
  • Adapter to go From 4-Way to 7-Way on 2023 Hyundai Palisade
    To go from a 4-way like the Tekonsha 4-Way part # C43FV to a 7-way on your 2023 Hyundai Palisade you'd need a 7-way adapter part # 37185. Or if you need to install a brake controller too you'd instead want the part # ETBC7 with a controller like the P2 part # 90885. To activate the reverse light circuit the yellow wire would need to run to the reverse light circuit of the vehicle.
    view full answer...
  • Recommended 7-Way Connector for a 2017 Jeep Wrangler JK
    To add a 7-Way/4-Way combo vehicle connector to your 2017 Jeep JK, I recommend the Universal Installation Kit for Trailer Brake Controller item # ETBC7. The kit includes a pre-wired 7- and 4-way trailer connector that mounts easily at the rear of your Jeep with an included bracket. This kit is designed for use on a vehicle with an existing 4-way flat trailer connector and plugs directly into it.  You will then connect the blue wire to the blue wire on the Tow Pro Elite Brake Controller...
    view full answer...
  • Parts Needed to Install 7-Way on 2014 Nissan NV 2500
    There's only one way to install a 7-way on your 2014 Nissan NV 2500 and it involves installing a 4-way first like with the Curt part # C56148 which is by far the best option that is the most reliable. And then to convert it to a 7-way and install a brake controller you'd need the part # ETBC7. If you don't plan to install a brake controller you'd instead need the part # 37185. For a brake controller the Redarc Tow Pro Liberty # RED57FR is a really great option that only puts a small knob...
    view full answer...
  • Installing A Reese Brakeman Controller In A 202 Ford E250 With Factory 4-Flat
    Hey John, I can definitely help with that. The Reese brakeman controllers are compatible with the Tekonsha brand plug-and-play adapters. For your 2002 Ford E250 you can use the # 3035-P to plug directly in to the factory brake controller plug. You will also need item # 37185 to complete your wiring. The brake (blue) wire will need to be run from the brake controller back to the plug in the rear. The brake controller power and brake pedal wires are already run. A 12 volt hot lead from the...
    view full answer...
  • Trailer Hitch Recommendation for 2020 Hyundai Palisade
    Curt does make really great trailer hitch and we do recommend them highly. We have a fit for your 2020 Hyundai Palisade too with the part # C13427 but the part number you mentioned is not a fit. This is a mostly hidden trailer hitch with plenty of towing capacity. Check out the install picture and video link I attached to this page as well. For trailer wiring the easiest to install option is the part # CU94FR. If you wanted to do some towing you might be interested in etrailer ball mount...
    view full answer...
    Image 1 for
  • How to Activate Charge Circuit of 2020 Jeep Cherokee 7-Way
    The least expensive way to activate the charge circuit of your 2020 Jeep Cherokee Trailhawk's 7-way will be to run a length of 10 gauge wire like part # 10-1-1 (sold by foot) from the positive post of the vehicle battery to the 1:00 pin of the 7-way through a breaker like part # 9510.
    view full answer...
  • Trailer Hitch & Wiring for 2014 Ford Edge
    Both Draw-Tite and Curt hitches are good quality products. While one given hitch fit may favor one brand over the other in total they both offer excellent products. Curt hitches can sometimes have a nicer powder coat finish, and since they are made in the USA they do offer that appeal. Of the options available I suggest the Draw-Tite 2-inch Class III hitch # 75992 for its lower price and freedom from the Curt requirement of using a support strap with non-trailer loads like bike racks....
    view full answer...
  • Parts Needed to Install 7-Way on 2023 Kia Telluride
    I have a way to install a 7-way on your 2023 Kia Telluride but we don't have any custom fit options. Instead you would need to start with a 4-way like the Curt # C59236 and then you would need to convert it to a 7-way with the part # 37185. If the trailer has brakes instead of the 37185 you would need to use the # ETBC7 with a brake controller like the P2 part # 90885.
    view full answer...
  • Does 7-Way Trailer Wiring Have the Stoplights and Turn Signals on Same Circuit
    The 7-way you have installed on your truck would already have the turn signals and stop lights combined on the same circuit since that is standard for trailer wiring and there isn't a way to wire up a 7-way with the circuits separate. Now if there's a third brake light that you want to illuminate on your camper you would need to get that circuit directly from the stoplight circuit that you said was separate on the truck wiring (not the trailer wiring).
    view full answer...
  • Will Brake Controller Plug-In Adapter C51322 Fit 2004 Ford Expedition And 2004 Ford E-350
    The Curt Custom Wiring Adapter, part # C51322 is designed to work with the # C74VV brake controller and will fit both of your vehicles if there is a factory trailer connector installed on the vehicle. If you have a 4-way connector on either vehicle then you will also need part # 37185. If your E-350 does not have a trailer connector you will first need to install a 4-way connector like part # 18252. You will then need part # ETBC7 to get a 7-way at the back of your vehicle. If there...
    view full answer...
  • Trailer Connector for Towing Camper With 1995 Dodge Ram Pickup
    In order for your trailer taillights to function properly, you'll need to install a trailer wiring connector on your 1995 Ram. The two most common types of trailer connectors are the 4-pole and the 7-way. I'll link you to a trailer wiring FAQ article that shows the differences between them. If your camper has a 4-pole connector, you'll use part # C55317. The wiring harness will install as shown in the installation instructions that I've linked for you. If it has a 7-way, there'll be...
    view full answer...
  • Comparing 4-way to 7-way Adapter Kits For A 2011 Toyota Sienna
    The Universal Installation Kit for Trailer Brake Controller # ETBC7 is your complete solution for converting over to a fully functioning 7-way connection plus 4-way while the Adapter 4-Pole to 7-Pole and 4-Pole # 37185 only provides your adapter for light functions and mounting bracket hardware. If you're still in the market for a brake controller, the Curt Echo Mobile Trailer Brake Controller # C51180 is a popular option allowing you to skip the need for mounting a controller in your...
    view full answer...
  • What Gauge Wire is Used for the Adapter That Comes with the # ETBC7 Kit
    The adapter that is used in the Universal Installation Kit # ETBC7 is the Hopkins # 37185. This unit has 16 gauge wires for the Green, Yellow, and Brown wires and then 12 gauge wires for the Blue, White, Black, and Purple wires. I have confirmed this with my contact at Hopkins.
    view full answer...


< Previous
123. . .88



Do you have a question about this Trailer Wiring?


Info for this part was:

Employee Joe V
Test Fit:
Joe V
Employee Nicholas E
Test Fit:
Nicholas E
Employee Shane T
Test Fit:
Shane T
Employee Randy B
Test Fit:
Randy B
Employee Joe B
Test Fit:
Joe B
Employee Jared G
Test Fit:
Jared G
Employee Brent H
Test Fit:
Brent H
Employee Shane H
Test Fit:
Shane H
Employee Robert C
Test Fit:
Robert C
Employee Conner L
Test Fit:
Conner L
Employee David F
Test Fit:
David F
Employee Bradley B
Test Fit:
Bradley B
Employee Jackie C
Expert Research:
Jackie C
Employee Mike L
Expert Research:
Mike L
Employee Sarah L
Expert Research:
Sarah L
Employee Robert G
Expert Research:
Robert G
Employee Patrick B
Expert Research:
Patrick B
Employee Michael H
Expert Research:
Michael H
Employee Jeff D
Expert Research:
Jeff D
Employee Reno H
Expert Research:
Reno H
Employee Jameson C
Expert Research:
Jameson C
Employee John H
Expert Research:
John H
Employee Brandon M
Expert Research:
Brandon M
Employee Adam R
Expert Research:
Adam R
Employee Lori W
Expert Research:
Lori W
Employee Jeffrey L
Expert Research:
Jeffrey L
Employee Zack K
Video Edited:
Zack K
Employee Andrew K
Video Edited:
Andrew K
Employee Joshua S
Video Edited:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Andrew L
Video Edited:
Andrew L
Employee Dustin K
Video Edited:
Dustin K
Employee Sue W
Video Edited:
Sue W
Employee Chris R
Video Edited:
Chris R
Employee Zach D
Video Edited:
Zach D
Employee Adele M
Updated by:
Adele M
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Updated by:
Alexander C
Employee Hannah L
Updated by:
Hannah L
Employee Kathleen M
Video by:
Kathleen M
Employee Alan C
Video by:
Alan C
Employee Jonathan Y
Video by:
Jonathan Y
Employee Thomas T
Video by:
Thomas T

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.