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

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

$32.33
Retail:$38.45
You Save: 16%
Custom Fit Vehicle Wiring
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1-800-940-8924 to order Hopkins custom fit vehicle wiring part number 37385 or order online at etrailer.com. Free expert support on all Hopkins products. Great prices and Fastest Shipping for Adapter 7-Pole to 4-Pole and 5-Pole. Custom Fit Vehicle Wiring reviews from real customers.
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  • Reviews (121)
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  • Videos (2)
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Hopkins Custom Fit Vehicle Wiring

  • 7 Blade to 4 Flat
  • 7 Blade to 5 Flat
  • Universal Fit
  • Wiring Adapters
  • Hopkins
  • Plug Only


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

Item # 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 An In-Depth Look at the Adapter 7-Pole to 4-Pole and 5-Pole

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:

Ratings & Reviews

4.8

121 reviews

by:

Quality products



by:

Great accessory at a great price.



by:

Very cool parts, quick service and delivery!



by:

Great service and website.. received quickly.



by:

High quality product, works great on my 2008 GMC Sierra.



by:

Quality products offered at reasonable prices. Prompt shipping



by:

Notification of receipt of order and of shipping was great. They could not have done a better job.



by:

Ordered this because I needed the 5 flat. Fits in perfectly to my Pollak 7-way. I'll let you know how the installation goes.



by:

This is a great feature if you have a 4 and 5 pin plug for different trailer hookups.



by:

Fantastic. Elliminates need for 2 separate harnesses. Many trucks already have a 7 pole connector and a 4 pole connector but nobody has a 5 pole connector so this kills 3 birds with one plug.



by:

This adapter takes the place of two! I have two trailers with different plug connectors, this product works for both eliminating the need for different plugs.



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:

This is my second same kind Brake controller. I hope to take advantage of the trailer connection for that 5th surge brake connection, yet have the 4 pin available for a lot of other stuff. Have yet to install but all looks good.



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:

It simplifies all the wiring harnesses and connectors that I had before for all my trailers. Hopkins is always good quality.



by:

Haven't used it yet, but it seems like a well made product.



by:

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



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. profile picture

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 profile picture

Ted

9/10/2020

Everything is still working great with no issues!!



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 profile picture

Capt.wanabe

7/23/2018

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



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. profile picture

Robin N.

7/21/2017

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



by:

I have ordered several items from eTrailer over the last few years. Items are always top quality, including this recent purchase. Customer Service staff are great, and rapid shipping. I could not be happier with my purchases.



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 profile picture

Jimmy

4/7/2019

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



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 profile picture

David

3/28/2020

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



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!


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Show More Reviews

See what our Experts say about this Hopkins Custom Fit Vehicle Wiring

  • All Trailer Lights Work Fine Except Brake Lights Will Not Work
    On a trailer the brake lights and turn signals operate on the same wire/bulb. So, it is odd when the turn signals work, but the brake lights don't. There are 3 possible causes for this that are more likely than any of the other possible causes. First there could be a problem on the vehicle side. Use a circuit tester such as # PTW2993 to test the vehicle side trailer connector while someone steps on the brakes in the tow vehicle. If there is no power on any of the pins for this test then...
    view full answer...
  • Troubleshooting 2012 Ford F-250 with No Trailer Running Lights, Fuse Good
    The easiest way to test a relay is to substitute it with a known working relay and then see if the circuit then starts to work. I would almost guarantee this is your problem based on what you described. Most likely the power would go to the relays and then to the fuses since the relays are what power the circuit and the fuse is what protects the circuit. A relay can go out without blowing a fuse though in case you were wondering if your fuse being good was an indicator of the relay still...
    view full answer...
  • Front Lights on Trailer Work But Rear Lights Dont Work and Get Hot
    That definitely sounds like a ground issue. If your wires are hot and you are getting signals to the lights in front of them then you need to check your grounds. Not only do you have a main ground wire but each light itself will have a ground. Check to make sure that your grounds are secure and connected to a clean, bare-metal surface. If those look good then the only other thing would be some damaged wiring. Check from the working lights to the lights that don't work and look for any...
    view full answer...
    Image 1 for
  • Only Left Side Brake and Turn Signals Working on Boat Trailer
    This sounds like a ground problem. A loose, broken, or corroded ground connection can cause all sorts of unwanted problems for electrical components including trailer taillights. I would start with checking for a proper ground at the taillight itself. Trailer tail lights can be grounded in one of two ways. The first way is the tail light assemblies can be grounded by a separate wire coming out of the back of the tail light and attached to the trailers frame. The second way is the tail...
    view full answer...
  • Adapting a 5-Way Flat Vehicle Side Trailer Connector to a 4-Way Flat for Towing Lights
    You may be able to plug in the 4-Way flat into the 5-Way flat without an adapter. There will just be one pin that is not used by the 4-Way left over. All the other functions will still work. The pin furthest from the ground pin (on the vehicle side 5-Way) will be the one that is not used. If the two connectors will not fit together, you can use Wiring Kit, # HM47890. You will just need the trailer side of the kit. You will have to replace the connector on the tow lights with the trailer...
    view full answer...
  • Will Adapter 7 Pole to 4 Pole and 5 Pole Work On My 2010 Toyota Tundra With Tow Package
    If your 2010 Toyota Tundra is equipped with tow package and factory 7-way on the back of your truck then yes the Adapter 7 Pole to 4 Pole and 5 Pole, part # 37385 will match up perfectly. The 5 pin flat connector on your trailer will plug directly into the 5 pin outlet on part # 37385.
    view full answer...
  • Troubleshooting Trailer Brake Lights on Vehicle Side Harness on 2001 Chevy Express Van
    It sounds like there is an issue with the vehicle side wiring. Since you know there isn't a bad fuse, I recommend checking the wiring itself for a short using a circuit tester like # PTW2992 to determine the point where power stops flowing in your wiring. I also recommend checking the ground connection of the wiring harness like # 118240 as a bad ground that isn't bare metal to metal can have one function that doesn't work fairly easily. If you don't have factory wiring, I recommend...
    view full answer...
  • Troubleshooting Trailer Brake Light Circuit of 2004 Chevy Silverado Not Active
    Hey Joshua, check the third brake light or CHMSL fuse under your hood. That is probably the issue as it is known to blow easily on your generation Chevy truck.
    view full answer...
  • Do I Need To Use Additional Tow Lights When Towing A Car On A Tow Dolly?
    Hello Tom, thanks for reaching out. If your tow dolly already has brake lights that are DOT compliant, you actually would not need to add additional lights. If you still want to add a separate set of tow lights, the best way to do this is using the 7-way plug on your RV. Since the 4-flat is already taken, you can use an adapter for your 7-way like part # 37385 to hook up the additional 4-flat.
    view full answer...
  • Recommended Wiring Harness for a 2024 Ford Maverick Pulling a Boat
    If your 2024 Ford Maverick doesn't have a 4-way connector you will need the Curt T-Connector Vehicle Wiring Harness item # C59DR you were looking at. This harness is custom fit and plugs into your Maverick's wiring harness, which is located behind the tail lights. To add a 5-pin to control a brake actuator you'll want to add the Curt Trailer Connector Adapter item # C57187. They don't make custom fit 5-ways. I have linked installation videos below to help you get these parts set up. If...
    view full answer...
  • Why Would a Right Trailer Taillight Stay on After Vehicle is Turned Off
    Typically when a trailer function stays on after the vehicle has turned of the problem is a fried aftermarket 4-way converter box. Or, if the lights are LEDs sometimes you will see the lights dimly lit. If you have an aftermarket 4-way converter box installed for trailer wiring on your vehicle most likely it has shorted out. Check out the video I attached that details how to test it. These don't usually short out for no reason, before you replace the harness you will want to find the...
    view full answer...
  • Troubleshooting Trailer Blinkers that Both Blink at the Same Time
    You have a short between the stop/turn circuits of your trailer wiring. Normally the blinker/stop circuit for each side of the trailer goes to either side of the trailer separately but in your situation the two wires most likely have exposed wire between them which is allowing the voltage from either side to transfer to the other as well. You'll need to go over the wiring of the trailer to track down the short and fix as needed.
    view full answer...
  • Troubleshooting Trailer Wiring that Works with One Truck But Not Another
    It could be a somewhat weak ground on the trailer that allows the lights to work with one vehicle but not with another. What you can try doing is running a ground wire from each of the light assemblies back to the main ground of the trailer. That should help especially if you have a fold away style coupler on your boat trailer.
    view full answer...
  • Bypassing TIPM for Trailer Wiring Fix on 2004 Dodge Ram 1500
    The TIPM setup of your 2004 Dodge Ram 1500 which handles your trailer wiring is a huge pain. At this point I would cut your losses with it and bypass it for the trailer wiring. All you will need is the Upgraded Circuit Protected Tail Light Converter Hardwire Kit # 119178KIT along with 4-Pole to 7-Pole Adapter # 37185 if you do not have a brake controller or # ETBC7 if you do have a brake controller.
    view full answer...
  • How to Remove & Replace Factory Twist-In 7-Way Trailer Connector on 1999 and Newer Chevy/GMC Trucks
    Take a look at the video I have linked that shows installation of 7-Way trailer connector # PK11916. In this video it shows not only what the twist-in connector looks like but also how to remove it in order to replace it. If this is the type of factory 7-Way you have then # PK11916 will fit in place of the factory 7-Way.
    view full answer...
  • Troubleshooting Trailer Brakes That Engage When Silverado Running Lights Are Turned On
    There are several potential causes for your issue. You could have a corrosion problem in either the vehicle trailer socket or the trailer plug. Because of the many circuits in a 7-way connector it is possible for corrosion, dirt or moisture to bridge two adjacent circuits together. When this happens one function leaks over to the wrong pin. If for example a running light circuit became bridged to the trailer brake circuit the brakes would engage whenever the truck's lights were on. Inspect...
    view full answer...
  • Trailer Has Separate Turn Signals that Come On with Brake Lights
    If the Coleman pup has separate turn signal lights then that is the issue. Trailers typically have what is called a 2-wire system with the brake lights and turn signals on each side sharing the same circuit and bulb. Either someone tried to install amber turn signals on the trailer but did not realize that it works on a 2-wire system, or they wired in the turn signals to the brake lights because the vehicle side connector had a 2-wire system and they could not operate the separate turn...
    view full answer...
  • Trailer Ground Wire Gets Hot and Smokes when Connected to Dodge Truck
    It sounds like either that is not the ground wire or there is a short to ground somewhere that you will need to track down. First, on the trailer, the one covered pin is the ground so make sure that is the wire you are attaching to a clean and corrosion free bare metal surface on the frame. A bad ground would also explain the lights no working. If the 7-Way on your truck is wired differently than standard, that could be a problem too. I have included a link to our FAQ on trailer wiring...
    view full answer...
  • Right Turn and Brake Lights Not Working on a Horse Trailer
    This is a classic ground problem. When there is more load on a circuit, like when the running lights are on, and you add more load by applying the brakes or a blinking signal, that is when ground problems show up. The usual suspects for this problem are dirty trailer connectors and corrosion. Start by checking the vehicle and trailer side connectors for dirt/corrosion on the pins and around back were the wires attach. Make sure that the main trailer connector ground is attached to a...
    view full answer...
  • Installing a 7-Way Trailer Connector and Brake Controller on a 2006 Ford Expedition
    On your 2006 Ford Expedition, there should already be a factory installed trailer connector. It will either be a 4-Way flat or a 7-Way blade. If your vehicle has a 4-Way flat, you will need to add Adapter 4 Pole to 7 Pole and 4 Pole, # 37185. On this connector, you would plug your 4-Way into the corresponding plug on the adapter. The remaining wires would need to be hardwired. Take a look under your vehicle behind the driver side rear tire and the bumper for the trailer wiring. There will...
    view full answer...
  • Trailer Lights Do Not Work when Connected to 2011 Chevy Silverado but Do Work with Other Vehicles
    If your 2011 Chevy Silverado came with a factory tow package (or even if it did not), there may be some connections that you will need to make under the hood to make everything fully functional. You can take a look at the FAQ article I have linked at the Finalizing Connections for the Brake Controller section. It is also possible that you may be missing relays and/or fuses associated with the tow package wiring. You can use the owner's manual to make sure that you have checked all of them....
    view full answer...
  • Trailer Brake and Turn Signals are Not Working but Running Lights Work
    If you are using an adapter like # 37385, it could be that the adapter is not pinned out the same way as your trailer requires. What you can do is test the functions on the trailer connector on your vehicle with a circuit tester like # PTW2993 if needed to make sure that all of them are working properly. If they are then you know the problem is behind the vehicle side connector. If they are not working properly on the tow vehicle it could still be a blown fuse or relays that needs to be...
    view full answer...
  • Troubleshooting No Trailer Brake Lights on 2002 Chevy Silverado 2500
    It sounds like a short on that circuit somewhere deep in the harnesses of the truck. I wish there was an easy way to fix it. Typically it's just a blown CHMSL fuse on your truck which is VERY common with this problem. I'm actually shocked you checked that fuse and it's still good. Since other circuits are hit or miss it might be best to just bypass the factory wiring and wire in a converter box like the # 119250KIT which will wire to the factory wiring of the truck instead to get the signal...
    view full answer...
  • How to Install Optronics MCL61AB LED Trailer Marker Light
    Did you mean the Optronics MCL61AB which we offer as part # OPT66FR? I suspect that the extra white wire you mention is simply an additional ground wire. To wire the # OPT66FR, you'll need a mounting bracket like # A65PB. The lamp grounds through the bracket's mounting hardware (as long as its mounted to the trailer frame or to metal that's in direct contact with the trailer frame) and the black wire goes to the running lamp circuit. You can see an install video by clicking the provided link.
    view full answer...


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