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

Adapter 7-Pole to 4-Pole and 5-Pole

Item # 37385
Retail:$30.45
Our Price: $28.85
You Save: 5%
Trailer Wiring
Add to cart
In Stock
Adapter 7-Pole to 4-Pole and 5-Pole Multi-Function Adapter 37385
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
Great Prices for the best trailer wiring from Hopkins. Adapter 7-Pole to 4-Pole and 5-Pole part number 37385 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
  • All Info
  • Reviews (115)
  • Q & A (0)
  • Videos (2)
  • Photos

Hopkins Trailer Wiring - 37385

  • Wiring Adapters
  • Multi-Function Adapter
  • 4 Flat
  • 5 Flat
  • Plug Only
  • Hopkins
  • 7 Round - Blade


Features:

  • Wiring Adapter - converts the 7-way trailer connector on the vehicle to a 4-way or 5-way connector to match the trailer


If your truck has the connector on the left, and your trailer has one of the connectors on the right, you will want this adapter.
30300 18004
Vehicle End Trailer Ends


47385 Adapter 7 Pole to 4 Pole and 5 Pole - TAP # 37385




California residents: click here


Video of Adapter 7-Pole to 4-Pole and 5-Pole

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Hopkins 7-Pole to 4-Pole and 5-Pole Adapter Review

Hey everybody, Ryan here at etrailer. Today we're gonna be checking out the Hopkins trailer wiring adaptor plug. So this is gonna go from a seven-way round not only to a four-way flat, but also a five-way flat. So let's check it out. And if your vehicle has a seven-way round type connector like mine does here, and you have to tow a trailer that has a four-way flat or five-way flat, this is gonna allow you to do that. So the way this will work is you'll plug into your seven-way round connector and then choose the appropriate type of wiring.

So we're hooked up to a small little fishing boat here. It has a four-way flat. We can open up that cap, take our trailer wiring, and plug right into it, and that's gonna allow all the signals to transfer back to our trailer, giving us all the lighting signals to keep us safe and legal. And what a lot of people like about this one is this honestly gives you the ability to tow or hook up to, wiring-wise, just about any trailer. So let's say maybe you have a utility trailer that has a four-way flat and then maybe a boat trailer that has brakes or something on it that has a five-way flat.

Having this one adapter is gonna allow you to pair up to all those different types and not have to keep two or three of these rolling around in your glove box or whatever the case is. These signals that this is gonna send back for our four-way flat will be your taillights, your brake lights, and your turn signals. So you have all your bases covered there. Five-way flat is gonna send out all those same lighting functions except that fifth pen is gonna be for a reverse light or backup circuit. Generally you'd see that on marine or boat trailers that are a little bit larger that have surge brakes, or even if maybe you have a utility trailer and you want to set up reverse lights on it, something along those lines.

That's where the five-way flat is gonna come into play. As far as the construction quality goes, I feel like it's pretty well-made. Feels like it's thick plastic, don't feel like a piece of junk by any means. It does fit nice and tight, at least into my seven-way. So that's good.

You know, don't worry about it having a loose connection or something, but I like how they give you the caps too because if you want to leave this thing in here, say if you tow a lot or something, or just don't feel like storing it inside the vehicle, at least you can keep those terminals protected against corrosion and whatnot. And honestly, from time to time anyway, it's not a bad idea to apply di-electric grease to 'em. And that holds true for your trailer end as well. Just keeps it in better shape and you can expect to get a little more life out of it. Something that I have ran into the past with using certain types of adapters is every trailer end might be a little bit different. These you don't see too often, but they are out there where they're kind of boxed in and in the past I've had issues getting 'em to hook up. And with this particular one, that's really not the case. It still fits right over it and creates a good tight seal. We do have a trailer here that has a five-way flat. And just to kind of show that off, you don't want to give the four-way all the love today. We'll just show you how it works too. You know, pretty standard connector and don't run into any issues in terms of getting that plugged in into our adapter plug. Other than that, at the end of the day, you know a great solution for those of you that have different types of trailers or different types of wiring, or if you're just unsure of what you might be pulling in the future. This is gonna allow you to hook up to all those different types for the most part. So can't really ask for too much more. But that'll about do it for our look-at of the Hopkins seven to five and four-way adaptor plug.

Customer Satisfaction Score:


Customer Reviews

Adapter 7-Pole to 4-Pole and 5-Pole - 37385

Average Customer Rating:  4.8 out of 5 stars   (115 Customer Reviews)


by:

The 4/5 flat adapter arrived as described. Very good quality.



by:

You don’t often run into a flat 5-pole connector, but it’s nice to have it covered!



by:

Wish I would have found this earlier, Super addition to my towing kit in my Atlas



by:

Great service.



by:

In my quest for a 7 pin to 4 pin connector to operate lights on my luggage rack my search led me to etrailer. Initially I spoke with Derek who was very helpful and sent me a connector that was 7 to 5 pin as that's what I thought I had. Turns out I was wrong so I called back to order a 7 to 4. This time I found Ashley and she quickly mailed me the 7 to 4.
These two employees were most helpful and very courteous in my dealings with them I'm happy to recommend etrailer for these kinds of products. Give them a try!

Jim L.

7/29/2018

Works fine. Only used it a few times but no problems.



by:

These plugs work great. I use it for my boat trailer (5 Plug), Jetski trailer (4 Plug) and a Car Hauler Trailer (7-way). Very simple to use. Highly recommend it you use multiple trailers with different plugs and braking systems.

Ted

9/10/2020

Everything is still working great with no issues!!



by:

Provides a quick and simple solution for connecting a trailer with a flat-4 or flat-5 plug to my truck with its round 7-way plug.

Robin N.

7/21/2017

We recently towed a rental trailer from Maryland to New Mexico. This connector worked perfectly!



by:

Product was delivered in a timely fashion and matched the part ordered. Quality was excellent and provided the features per price point that was desired. So far, no problems in use. It is now part of my basic trailering kit. Other products are available that have more features but they are larger and cost more. For my use this is right on. Product support and useful information from etrailer is consistently excellent.

Capt.wanabe

7/23/2018

After one year the wiring adapter continues to work well. I would not change my original review.



by:

Works well.



by:

Exact replacement for the one I lost, had no problem finding it at etrailer since I had previously bought hard to find parts I needed when replacing worn parts on my boat trailer. Thanks etrailer.

Jimmy

4/7/2019

Working great, I am causious about not losing it again, thanks again.



by:

The adapter fit tightly and worked well. Be careful attaching and detaching the trailer harness so, you don't bend the bottom metal, male connector.

Everything installed correctly the first time and worked on my 2011 Honda Pilot. What a relief. It took me about 2.5 hrs because, I had to figure out fasteners for the bumper, existing wiring harness, etc. so I didn't break anything. Make sure you have a center punch, sharp metal drill bits and oil to pilot holes for self tapping screws. I am very happy with the harness and adapter.



by:

Well made and reasonably priced.



by:

Was exited when I found this on etrailer's website...I have 2 different trailers with 2 differents light harness connectors. This works great...no need to switch out or have two or more adaptors in truck!! Highly recommend!



by:

Overall...much better than going through the dealership for the sake of time and money. The online videos hit all they key points and steps bit there was some mechanical ingenuity required on my part. Mounting the bracket was the most challenging part to install and it was correctly represented in other reviews.

Personally, I wanted the 7 pin connector flush to the bumper and had to bend the mounting bracket and cut out the plastic bumper to get a tight fit. Looking back however, I think that if I would have cut out just enough of the bumper to accommodate the angle of the mounting bracket (when attached to the frame) then I would have still achieved both a solid connection and clean, professional look.

All in all, I'm very satisfied with the product and instructions received from e Trailer and staff.



by:

It was great and worked exactly as it was supposed to until my dog pulled it out of the receptacle and chewed it to bits.
I put an external tire carrier on my car and was using the three hole side to power my relocated license plate.
The rig lasted through all sorts of weather and terrain like a champ. I got about 9 months out of it before it was devoured. I'm sure it would have lasted for years if not for the >-< dog.



by:

This adapter works perfect. It easily installs into the round 7 pin connector. The connector worked as all lights were lit and I was able to back my boat trailer into position with no problems. The 5 flat is used for the inclusion of the surge brakes on my boat trailer. I would recommend this to anyone needing the conversion adapter.



by:

Good product. Works well and is very convenient to have both 4 and 5 pin connectors. Only issue is dust cover on 5 pin sticks to ground pin when you pull it off with the tab and can bend the ground pin.



by:

The Adapter made a quick and easy connection between my truck and the trailer. All lights functioned properly.

Great adapter at a great price.



by:

As always, product arrived quickly and well-packed. Good quality and is working well on my vehicle. etrailer can be counted on for quality and customer service.

David

3/28/2020

No problems, never give it a second thought. Can depend on it to do the job.



by:

The wiring kit fits perfectly. I had a small problem with the operation of the brakes on my trailer but a quick call to the great service department and my problem was quickly rectified. I will do business again.



by:

Just what I needed, have a boat and two wheel trailer with different plugs , ordered the weather tech mud flats also for my 2011 gmc 1500, they were easy to install and look great, all items where to me in three days. Great job etrailer



by:

Fits the round plug on the vehicle perfectly. Haven't hooked it up to the flat wire yet, but assume it should be fine. Getting this adapter with the covers for the 4 & 5 flat is absolutely the right way to go. I'm towing a 5500 lb boat with surge brakes.
Jesse did an outstanding job of helping me.



by:

This trailer light adapter allows me to haul 2 different trailer with one vehicle. Delivery was in 3 days and I also purchased a 5 wire trailer wiring harness to match



by:

I find this adaptor to be very useful as I own and frequently tow, different size trailers all with different plug connectors. Nothing is worse than not having the right connection to make your trailer connection.



by:

Great service, easy ordering. Love the adapter, no more rewiring to make plugs match.


25
115
Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring

  • 7-Way to 5-Way Adapter for Boat Trailer with Electric Reverse Lockout
    Yes, there are 7-Way to 5-Way adapters that you can use. If you want one that is just a 7-Way to 5-Way then # A75TB is a great option. I have linked a video review for you. If you want something that is a little more versatile we have # 37385 which is a 7-Way to 4- and 5-Way. I have linked a video review of this adapter as well.
    view full answer...
  • Trailer lights
    It sounds like there is either fuses or relays blown on the truck or the trailer connector on the truck side has corrosion in or on it. Checking the fuses and relays is easy. Just locate the tow package fuses/relays using the owner's manual or the legends on the fuse panel lids (many vehicles have fuse panels in the cab as well). For a relay the easiest way to check for a bad one is to use a known good one in its place. Inspect the trailer connector and make sure it is clean and free of...
    view full answer...
  • Can 7-Way Adapter be Used with a 2002 Chevy Silverado
    Yes the Trailer Connector Adapter, part # 37385, will work with the factory 7-Way on a 2002 Chevy Silverado 2500. You will not retain the 7-Way, but you will have the option to use 5-Ways, or 4-Ways.
    view full answer...
  • Trailer Wiring Adapters to Convert 7-Way Vehicle Connector on 2014 Honda Pilot to 4-Pole Flat
    The TowReady T-One Vehicle Wiring Harness # 118558 that you referenced is intended for use in the 2014 Honda Pilot without the factory tow package. If your Pilot has the tow package the correct wiring kit for it is # 118265 which includes a 7-way socket and relays. If you have a functioning 7-way on the vehicle already and just need compatibility with a 4-pole equipped trailer, you can simply use an adapter like # PK12716 from Pollak. This simply plugs into the 7-way and converts it to...
    view full answer...
  • 7-Way to 4- or 5-Way Adapter for 2013 Honda Ridgeline w/Factory 7-Way and PWC Trailer w/4 or 5-Way
    Yes, there are adapters to go from the 7-Way on your 2013 Honda Ridgeline to a 4- or 5-Way trailer connector on your trailer. A popular adapter for this situation is # 37385. It plugs into the 7-Way on the vehicle and has separate 4 and 5-Way ends on the other side for the trailer. You usually see 5-Way trailer connectors on boat trailers or any trailer that has an electric reverse lockout on a surge break actuating coupler.
    view full answer...
  • Troubleshooting Trailer Lights Without Running Light Function
    When you have some functions working on your trailer and others that aren't working, you start with the vehicle wiring harness. Use a circuit tester like # PTW2993 to test each function before your trailer is connected. If each function works correctly then we know the issue is with the trailer wiring. Clean both sides of the connection with some sand paper to ensure you have a good clean connection. Often when one function doesn't work it is due to a bad ground connection on the trailer,...
    view full answer...
  • Trailer Tail Lights Dim When Brake Pedal Is Depressed
    The most likely cause of the tail lights dimming when the brake pedal is depressed will be attributed to a poor ground. Therefore, in order to fix this issue you will need to either try and clean the ground point or run a separate ground wire from each tail light up to the trailer connector. This should then fix your issue but if it does not then please just let me know and I would be happy to further troubleshoot this issue for you. If you need extra wire to run the separate grounds and...
    view full answer...
  • Trailer Lights Turn Off when Headlights are On and Brake Pedal is Pressed
    This sounds like a ground issue or a possible short. Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then use another function like a turn signal or brake light. A short could come from a dirty or corroded trailer connector. Make sure that the vehicle side and trailer side connectors are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces. The...
    view full answer...
  • Troubleshooting Common Trailer Wiring Issues on 2004 Chevy Suburban & 2006 Cadillac Escalade
    That's a tough one, indeed. Usually, we can isolate the cause for a wiring problem by substituting an alternate vehicle or trailer. My initial suspicion is that both vehicles have a ground problem. A weak ground will allow some lighting functions to work while others may not. I suggest you check the white ground wire for each vehicle's wiring harness to ensure these are tightly affixed to a clean bare metal spot on the frame. If the grounding points are rusty/greasy clean and sand them...
    view full answer...
    Image 1 for
  • Trailer Lights do not Work Properly When Truck is On
    The light problems you are having sounds like the elusive ground problem that haunts many trailer owners and shops. Ground problems typically appear when more power is applied to the taillight circuits and can cause erratic lighting or no lighting at all. The first step in troubleshooting is to check the trailer side and vehicle side connectors for any corrosion and repair or replace as necessary. Next, test the vehicle side trailer connector using a circuit tester like part # PTW2993....
    view full answer...
  • No Turn or Brake Signals While Towing With 2018 Ford F-150 After New 7-Way Installation
    When you say receiver I believe you mean a trailer wiring connector. The trailer connector does need to be grounded to a clean bare metal surface of the truck's frame which is most likely causing the issues with the lights. Another thing to check for is any corrosion on the pins or bent pins of the trailer connector which may be causing a bad connection. If there is corrosion you can lightly sand it off but it sounds like you have a classic ground issue especially since you said the trailer...
    view full answer...
  • Trailer Right Tail Light and Turn Signal Do Not Work with Running Lights On
    This sounds like either a bad ground connection or there is too much amperage draw from the trailer for the tow package wiring on the vehicle. Bad grounds usually show up when there is more load on a system. The bad ground can be anywhere in the system, not just at the light. The first step is to isolate the issue by disconnecting the trailer and testing the vehicle side trailer connector using a circuit tester such as # PTW2992. Have someone sit in the vehicle and run through the lighting...
    view full answer...
  • Troubleshooting No Brake Signals on Vehicle 4-Pole Wiring Harness
    In 4-pole trailer wiring the stop light signals are combined with the turn circuits on one circuit for each side of the trailer. Typically a yellow wire carries left stop/turn signals and a green wire carries right stop/turn signals. Please refer to the linked photo of a 4-pole that shows these function and pin assignments. If you are using a wiring adapter like the 7-Pole to 4-Pole and 5-Pole # 37385 you can remove it and test the 7-way socket on the vehicle to ensure the stop light signals...
    view full answer...
    Image 1 for Image 2 for
  • Troubleshooting Trailer Taillights that Don't Work Right When Vehicle Headlights are On
    The problem you are having is indicative of a bad ground connection. Ground issues usually show up when there is more load on the system. In this case the constant draw of the head lights is causing too much power draw for the weak ground when you try to use another function. Make sure that the main trailer connector ground and the grounds for all of the lights are attached to clean and corrosion free bare metal surface. Anything placed between a ground wire and the metal frame can interrupt...
    view full answer...
  • Troubleshooting Trailer Taillights Where None Work
    So the problem is on your trailer then if the trailer wiring harness works to light up your tailgate lights. Make sure that the trailer side connector are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces. The light grounds should also be attached to clean and corrosion free bare metal surfaces. If there is anything between a light ground and the metal trailer frame or if the trailer has an aluminum...
    view full answer...
  • Determining if Reverse Light Circuit is Live on 2007 Jeep Grand Cherokee 7-Way Trailer Connector
    If the 7-Way is factory installed on your 2007 Jeep Grand Cherokee, then the reverse light circuit is more than likely connected as it should be. It would be the center pin. I have included a picture of a 7-Way vehicle side connector that shows the functions. To test to see if the circuit is live or not you will need to test the center pin with a circuit tester such as # PTW2993 if you need one. Chock the vehicle wheels and engage the emergency brake and then have someone sit in the Jeep...
    view full answer...
    Image 1 for
  • Trailer Running Lights Will Not Work and Blow Fuse on Truck
    If it is the tow package running light fuse that is blowing then there is most likely a short in the trailer wiring or in the trailer or vehicle side connector. What you will want to do first is make sure both the vehicle side and trailer side connectors are clean and free of corrosion inside and out. Next make sure the main trailer connector ground and the grounds for all of the lights are attached to clean and corrosion free bare metal surfaces. Then you will need to trace the wiring...
    view full answer...
  • What to Check When the Lights on a Trailer are not Working Properly
    As all the wiring harnesses available for a 2012 Toyota RAV4 are plug and play, I think it is actually something on the trailer that is causing the issue. I suggest checking all your ground connections to make sure one hasn't disconnected or become corroded. A bad ground can cause any number of weird things to happen, and this definitely sounds like what is going on. You will need to make sure everything is grounded to bare metal that is not aluminum. Each light should also have its own...
    view full answer...
  • Troubleshooting Truck Taillights Stopped Working when Trailer Plugs In
    Sounds like there's a lot of wiring issue present that we really can't get too specific on helping with. Best solution would be to check out the trailer wiring at the rear of the truck and see if you can find any obvious shorts like cut or exposed wire and fix as needed. That would be my guess as to where it is coming from.
    view full answer...
  • Troubleshooting Why Truck Has Running Lights But Trailer Does Not Have Lights When Connected
    You will want to use a circuit tester like part # PTW2993 and do some testing. Have someone run through the functions on the truck while you check the pins on your trailer connector at the back of your truck. Make sure they are clean and free of corrosion, and that the ground is securely attached to a clean metal surface. A loose ground will cause all kinds of issues. You will also want to check the fuse panel and see if there is a towing fuse needed and make sure it is not blown or missing....
    view full answer...
  • Troubleshooting 2003 Chevy Tahoe that 7-Way Stopped Functioning
    If the trailer wiring fuses of your 2003 Chevy Tahoe are good and the 7-way still isn't working properly the problem is either that there is corrosion on the 7-way that would need to be cleaned off with fine grit sandpaper or the wiring to the connector itself is damaged somewhere between the connector and the vehicle fuse block. Check out the connector, most likely you will either find damaged wires behind the connector or corrosion that needs to be fixed or there is corrosion on the...
    view full answer...
  • Troubleshooting Stop/Turn Signals on Trailer Wiring Not Functioning on a 2005 Nissan Frontier
    It really sounds like you are missing the two blue relays like part # 38666-1 from the relay box under the hood of your 2005 Nissan Frontier. I would recommend you double check that you replaced the correct relays. In some of the Nissan relay boxes there are two sets of blue relays. It is possible that you replaced the wrong set of two. Another possibility is that the grounds of your trailer aren't sufficient. Check the grounds of your taillight assemblies, make sure they are connected...
    view full answer...
  • Will Adapter PK12716 Work With a 2008 Chevy Pickup Towing a Boat Trailer
    Yes, adapter PK12716 will fit your 2008 Chevrolet Pickup factory plug as long as it is a 7-way plug. It should look similar to part # PK11916. It would have no problem connecting to the 4-way flat plug on your boat trailer. However, I do recommend double checking the style of your trailer plug, as 5-way plugs are very common on boat trailers. If you have a 5-way plug, it would look similar to part # HM37908. If you do happen to need a 7-way to 5-way adapter, you could use part #...
    view full answer...
  • Trailer Turn Signal and Brake Lights Dont Work But Running Lights Do
    Even if you have checked all of the connection points and fuses, there could still be a short in your wiring somewhere along the line. If you put proper protection on your soldering, the best protection would be using Heat-Shrinkable Tubing # DW05449 with Electrical Tape wrapped around the places that you soldered, then your splices should be okay. Otherwise the connections could jar loose, or in cold conditions they could become brittle and ineffective. If your connections look good,...
    view full answer...


< Previous
123. . .10



Do you have a question about this Trailer Wiring?


Info for this part was:

Employee Mike L
Expert Research:
Mike 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 Rachael H
Expert Research:
Rachael H
Employee Jeffrey L
Expert Research:
Jeffrey L
Employee Zack K
Installed by:
Zack K
Employee Ryan G
Installed by:
Ryan G
Employee Andrew K
Video by:
Andrew K
Employee Joshua S
Video Edited:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Adele M
Updated by:
Adele M
Employee Laura H
Updated by:
Laura H
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.