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

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

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Trailer Wiring
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Hopkins Wiring Adapters - 37185
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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. Lowest 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.
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Hopkins Trailer Wiring

  • 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

Item # 37185




California residents: click here



Customer Reviews

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

Average Customer Rating:  4.8 out of 5 stars   (549 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:

Working fine one year after being installed! Towing a Bushwhacker, I had to draw a wire to the battery for operating the camper electric brakes, and added a Curt Echo bluetooth brake controller.




by:

Your information on how to connect to controller wasted a lot of time on the adapter under the steering column. In my Ford Expedition, the existing connector was plugged in and Brown not Gray. It was a simple swap. Instead, I tore apart panels under dash looking for an unconnected gray plug. Also you should sell the proper adapter for the rear end connector also. A simple plug swap vs. cutting 2 wires on Ford's wiring harness wires and using butt connectors would save so much time. Also, having a long purple wire for backup lights (not used very often) and short leads for hot and electric brakes was really stupid. I had to add 1 ft of wire to each - more butt connectors and potential for failure.


Comments
It is unusual that the 21 Ford Expedition will come with an adapter that is already plugged in under the dash to the left of the steering column. We do have listed as a tech tip for part # 37185
Adapter 4-Pole to 7-Pole and 4-Pole
$46.11
that an additional length of wire may be necessary to connect the 7-Way socket of part 37185 to the vehicles tow package wires which are along the rear frame rail.
-- Etrailer Expert Jenny N - 02/28/2022


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:

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:

Really great, I needed this 7 pole to connect my High Camp teardrop to my 2014 BMW X3 and the 4 pole for a small utility trailer. They both work beautifully




by:

The connector is standing up well for it's intended purpose. Easy to install.




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:

Nice quality adapter harness. I would highly recommend 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:

It was pretty straight forward at installing and does what it’s need to do.


Comments
It is still working strong. When something works you don’t give it much thought.
Weston - 04/22/2022


by:

AWESOME hitch unit. Strong, very easy to install (went in like a dream in 30 minutes), heavy duty, and right after I installed it on my 2011 Ford F-150 SuperCab I immediately towed a trailer with a 1971 MGB on it from North Carolina to Connecticut.


Comments
Awesome Hitch unit! Very strong and useful hitch unit. I dont even know it is on the truck until I need it. Wish I had purchased and installed this years ago, instead of trying to use the hitch ball installed on the bumper itself.
Jason M - 11/14/2021


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:

Very well made and fit bracket good




by:

This worked as expected. Perfect fit for my application




by:

Pretty easy to install and works as expected. The model in the video is a little different - the hole pattern is not quite the same. But the video was still useful.




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:

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:

I DO A LOT OF AFTERMARKET PART ORDERING ONLINE. IT IS ALWAYS NICE TO GET ON A SITE AND BE ABLE TO EASILY FIND WHAT YOU ARE LOOKING FOR, ESPECIALLY WHEN YOU DO NOT HAVE A PART NUMBER JUST A PICTURE AND IN SOME CASES THERE IS NOT MUCH OF THE PIECE LEFT SO IT MAKES ORDERING REPLACMENT PIECES DIFFICULT. MY TIME WAS WELL SPENT AND EASILY FOUND AND CHECK OUT WAS A BREEZE FOR A FIRST TIME SHOPPER ON YOUR SITE. THANK YOU TRACY WITH CALIBER COLLISION CSPG #816




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:

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:

Prompt delivery and works great.




by:

Well made and versatile.




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:

Lacking instructions




by:

everything good, we use etrailer for all our trailer needs



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Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring



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    I know exactly what is wrong. The red wire on the brake controller harness plugged into your 1999 Chevy Silverado is in the wrong location in its plug. This is a common issue. All you have to do is move the red wire to the correct location. I have included a picture showing how the various wires should be configured in the end that plugs into the truck.
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