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Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Vehicle End - 5' Long

Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Vehicle End - 5' Long

Item # HM37908
Our Price: $15.04
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Wire your vehicle to tow a trailer with this universal, splice-in wiring harness. Provides reverse function to release surge brakes. Corrosion-resistant terminals are long-lasting. Great Prices for the best trailer wiring from Hopkins. Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Vehicle End - 5' Long part number HM37908 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (14)
  • Q & A (0)
  • Videos (2)
  • Photos

Hopkins Trailer Wiring - HM37908

  • Trailer Connectors
  • Vehicle End Connector
  • 5 Flat
  • Plug and Lead
  • 0 - 5 Feet Long
  • Hopkins

Wire your vehicle to tow a trailer with this universal, splice-in wiring harness. Provides reverse function to release surge brakes. Corrosion-resistant terminals are long-lasting.


Features:

  • 5-Way flat trailer connector at the back of your vehicle plugs into the connector from your trailer to power your trailer's signal lights
    • Includes reverse function to release brakes when backing up
    • Ideal for use with marine-type trailers equipped with surge brakes
  • Simple installation
    • Hardwire to existing trailer wiring
  • Corrosion-resistant terminals are long-lasting


Specs:

  • Harness length: 5'
  • Wiring configuration:
    • White: ground wire
    • Yellow: left turn/brake light
    • Green: right turn/brake light
    • Brown: tail lights
    • Blue: reverse lights
  • 90-Day limited warranty


37908 Hopkins 5-Way Flat Connector - Vehicle End - 60"





Video of Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Vehicle End - 5' Long

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




Video Transcript for Hopkins Wiring Harness Review

Hey, everybody. Ryan here at etrailer. Today, we're gonna be checking out the Hopkins 5-way flat trailer connector for your vehicle side. For those of you that are unfamiliar with a five-way flat, this is essentially identical to kind of your classic four-way flat type connector. I'm sure a lot of people have seen them. They're just on about a ton of different medium size, smaller size trailers.

But this being the five-way though, you get one extra signal and that will be your reverse light signal. So, we have our ground wire, our taillight signal, our left turn as well as stop, right turn and stop, and this blue one is our reverse light. Now, there's a couple of different reasons you would wanna use this. I'd say probably the most common is for when you're towing a boat that has surge brakes on it. That way, when you're going to launch the boat or just even back it up into the garage or whatever, it'll have this reverse light signal and it won't lock the brakes up.

That way, you can actually back it up and not, you know, drag it across the ground. But you can kind of get creative too. I know there's some people that use this signal. They might have some small LED lights like as back up lights on their utility trailer and you can get a signal from this. That way, when you put it in reverse, it sends power out to whatever you have it wired up to.

So, you can kind of get creative on what you can do with this. Now, keep in mind this isn't gonna have a ton of amperage. So, you can't run a hundred lights off of it. But you got one or two lights on it, especially if they're LEDs, chances are good it's gonna power them right up and everything else. So, you know it's one of those deals that, in a sense, it's almost an upgrade over kind of your factory four-way or your regular four-way type connector.

And that kind of brings me to my next point. You are still able to use a four-way connector with this. So, let's say, if you have a boat trailer with the five-way and you also have the utility trailer with the standard four-way, you're still gonna be able to use the same connector. You won't need an adapter or anything. So, just for example, this is a trailer side, kind of your standard four-way and it'll still plug in. It'll still get its regular signals and everything else. So, like I said, you're not gonna need an adapter or anything like that. But I do want to mention, for this to work, you are going to need existing four-way wiring because this is essentially just a pigtail, right So, it's the connector and those five wires that come off of it. So, you are gonna have to kind of splice this into your existing wiring. And then, of course, you're gonna need to be able to find a way to pick up your reverse light circuit too. Whether it be your reverse light bulb, maybe your reverse light fuse in the dash or whatever, you're gonna need that power source, right So, that's just something to keep in mind whenever you're thinking about hooking this up to your vehicle. This particular harness is going to be five foot in length. So, changes are pretty good you're not gonna need all that wiring but it is good to have, right That way, if you do have to stretch it a little bit further, you got it, which kind of brings me to my next point. When installing this, it's probably a good idea, I would suggest picking up five heat shrink-type butt connectors, especially if you're gonna be keeping this outside since you have to splice in your existing four-way wiring. And it's gonna be pretty much the same for all vehicles. You splice in that four-way and then obviously, pick up your reverse light circuit, which like I mentioned earlier, you usually get it from your reverse lights, or one of your fuses, things like that. So, every vehicle is gonna be a little bit different but the idea is the same. I do wanna mention too, this isn't gonna come with a dust cover. You know how sometimes there's a little cap that'll plug over this So, that is something that you can grab separate and excuse me, you can also get, there's all different types of brackets and things of that nature where you can mount this up on your hitch. And this is even a good example. So today, I just put some of this black wire loom over our wires just to help kind of, kind of help it blend in a little bit better. So, you can use something like this as well if that's the style you're going for or the look you're going for. But other than that, at the end of the day, it's gonna be a good way to be able to use different types of accessories or pull those different types of trailers around that you otherwise wouldn't be able to. So hopefully, this kind of cleared up a few things and answered some of your questions on what this is, and what it actually does, and gets you going in the right direction. And that'll finish up our look at of the Hopkins five-way flat trailer connector for the vehicle side..

Customer Satisfaction Score:


Customer Reviews

Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Vehicle End - 5' Long - HM37908

Average Customer Rating:  4.9 out of 5 stars   (14 Customer Reviews)

Wire your vehicle to tow a trailer with this universal, splice-in wiring harness. Provides reverse function to release surge brakes. Corrosion-resistant terminals are long-lasting.

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The Glolight LED trailer set is the perfect replacement for my tow dolly. It is light weight and much more visible than the standard bulb lamp set the trailer was equipped with. Installation was quick and very easy, I will recommend this to all needing to change theirs out...



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Great Prices and Fast Shipping



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Thank you for shipping it out fast. Plan to use it for my motorcycle.



by:

Good product. Would be even better if wire was tinned copper



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The product was good, but it took 45 days to get it.



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Great product. Just what I needed.



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Just what I wanted. No frills straightforward ready to install. Good value and quality.



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Haven't used it yet but pretty straight forward.



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See what our Experts say about this Hopkins Trailer Wiring

  • Parts Needed To Add 5-Way Connector To Power Lights For Headache Rack On 2020 Ram 3500
    I have an option for you, but there is not a 5-way connector that is custom fit for your 2020 Ram 3500 and will allow to also hook up a trailer. I recommend using the Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Vehicle End - 5' Long Item # HM37908, and if it is not long enough to reach from the back of your truck to the headache rack you can add Bonded 4 Wire # 16-4B-1 and Primary Wire # 16-1-1 which are sold by the foot, to give you extra length. If you need to extend...
    view full answer...
  • Wire Gauge of 5-Pole Flat Vehicle Wiring Harness and Recommended 5-Flat Trailer Side Harness
    The 5-Pole Flat Vehicle Wiring Harness # HM37908 uses 16 gauge wire.
    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...
  • Troubleshooting Trailer that Applies Brakes When Vehicle is Put In Reverse
    It sounds like there is a short on the trailer side of the wiring. It sounds like the reverse light circuit is touching the brake output circuit which is causing the trailer brakes to apply when you put the vehicle in reverse. Check the connector on the trailer for corrosion and clean as necessary. Next check the wiring of the trailer connector as it leads back to the trailer. Most likely there is cut or exposed wire that is causing the short. I also attached a help article that has trailer...
    view full answer...
  • Parking Lights Do Not Work When Using a 7-Way to 4-Way Adapter with a 2008 Chevrolet 1500
    If you are seeing a TM on your trailer connector or on the 7-way to 4-way adapter, then the TM means tail/marker lights, or the parking lights, you are referring to. The first step that I would take is to get a circuit tester like part # PTW2993 and test each pin or blade on the connector on your 2008 Chevrolet 1500 to make sure it is functioning properly. If you have a signal for the taillights at the connector on your vehicle, then you know the issue is not with the vehicle wiring....
    view full answer...
  • Towing a Trailer Designed to be Towed by a Motorcycle Using a Truck
    Motorcycles and the trailers designed to be towed by them have turn signals that are separate from the brake lights. This is different than what regular trailers and vehicle trailer connectors have. they are set up with the turn signals and brake lights combined on the same circuits. The easiest thing to do is to wire up your truck with a matching vehicle side 5-Way such as # PK11502. This will be easy if your truck has turn signals on separate bulbs than the brake lights. You will just...
    view full answer...
  • Why Does the Running Light Circuit of a 4-Way Go to Both Sides of Trailer
    The brown wire of a 4-way connector is the running light circuit which goes to both sides of a trailer since that circuit is used for both taillights. What most people do is run the wires for both sides of the trailer to a single butt connector like # 05732-2 and then run a single wire back from there to the single brown wire on the 4-way. Some 4-ways have what's called a wishboned running light circuit like part # A35W42B which basically has two running light(brown) wires.
    view full answer...
  • How to Add 5-Way Wiring Harness to a 2012 Ford Edge
    We do have some options for you to add a 5-Way wiring connector on your 2012 Ford Edge, but the available wiring kits that tee in behind the tail lights don't come with 5-Way connectors. Your options to adding a 5-Way include using a wiring kit like the T-One # 118515 and then cutting off the 4-Way and splicing in a 5-Way like the Hopkins # HM37908, OR you can just install a 5-Way harness that splices in completely like the Tekonsha # 119177KIT. Attached are some videos you can check...
    view full answer...
    Image 1 for
  • Trailer Wiring Recommendation for Kia Soul and How to Make Adapter to Tow Trailer w Separate Wiring
    Basically, you will have to make an adapter. You will need 3 important parts. First you will need a vehicle to vehicle converter # 118158. Next, a trailer side 4-Way, # 18004. And finally a vehicle side 5-Way, # HM37908. It will be assembled like in the picture I have provided using butt connectors like # 05731-5. If the trailer has incandescent bulbs then this harness is limited to 1 brake/running light (dual filament bulb) and 1 turn signal bulb per trailer side. For trailer wiring...
    view full answer...
    Image 1 for
  • Subaru with 5-Way Flat Trailer Connector to Trailer with 4-way
    If your Subaru already has a 5-pole flat trailer connector like the Hopkins # HM37908, you will not need any additional parts to be able to connect with the 4-way flat on your trailer. You will just simply connect the two harnesses, and the additional pin on the Subaru's 5-way will just not be used.
    view full answer...
  • Troubleshooting Trailer Wiring that Locks Up Trailer Brakes When Connected
    It sounds like the 12 volt accessory circuit and the brake output circuit are wired backwards and that is why the trailer brakes lock up whenever you connect the 7-way on your vehicle to your trailer. What I would recommend you do is use a circuit tester like part # PTW2993 to test for voltage on each of the pins as a buddy applies the various turn signal circuits and brakes and then compare that to the 7-way diagram I attached. If it all checks out then the problem is the trailer wiring...
    view full answer...
    Image 1 for Image 2 for
  • Connecting 4-Way on Motorcycle to 5-Way on Trailer
    I think what might be going on here is that your trailer uses separate wiring (which is what a motorcycle would typically use as well) but your motorcycle has combined wiring, or at least is equipped with a converter to combine it before the connector, which is why it's equipped with a 4-Way instead of a 5-Way. With a combined wiring setup the turn and brake signals on each side of the motorcycle are sent along the same circuit. This is why the lights aren't working correctly on the trailer...
    view full answer...
  • Troubleshooting New Wiring Harness On Trailer For Reverse Lights
    In order to get the reverse lights to work on your trailer you will need a 5-way on your vehicle and also on your trailer. It sounds like you have wired the 4-way up but now you need the reverse lights. I recommend removing the 4-way connectors on both the towing vehicle and on your trailer and installing 5-way connectors. For the trailer side I recommend part # HM47913. You would attach the white, yellow(or light green), green, and brown wires to the same color on your trailer and then...
    view full answer...
  • Trailer Lights Only Work with Camper Plugged In To Shore Power
    It sounds like the trailer lights are tied into the interior lights and the trailer mounted battery and inverter. What I recommend is to have the trailer exterior lights bypass the rest of the wiring so that the trailer connector is isolated from the other lights. It seems that if everything is connected together through the battery or the inverter, including the trailer connector. Replacing the battery could solve the issue but I would still have the trailer connector separate from the...
    view full answer...
  • Wiring Options for a 2009 Chrysler Aspen Towing a Boat Trailer with a 5-Way Flat Trailer Connection
    Yes, the Tow Ready Custom Fit Vehicle Wiring for the 2009 Aspen by Chrysler, item # 118390, is the correct wiring harness for your Aspen and you will need one other item to complete the wiring to lockout the brakes on your boat trailer surge coupler. You can go one of three ways for this wiring. The easiest way in my mind is to install the # 118390 T-One and then splice the 5-Flat Vehicle End 5' Wiring Harness, item # HM37908, to the 4 like wires left by removing the 4-way vehicle end...
    view full answer...
  • How To Connect Trailer With 5-way Connector to 6-way Round Connector On RV
    I have an option for you, but you will need to make the adapter as there is not a 6-way round to 5-way adapter available, or change the connector on your trailer to 6-way round. To make an adapter you will need the Pollak 6-Pole, Round Pin, Trailer Wiring Connector # PK11604 which will plug into the 6-way round connector in your trailer, then use the 5-Flat Vehicle End 5' Wiring Harness # HM37908 to connect to the 5-way connector on your trailer. The other option is to cut off the 5-way...
    view full answer...
    Image 1 for
  • How to Determine Wiring Functions on Vehicle and Trailer
    First, you would need to determine the function of each of the wires on the vehicle side of the connector by using a circuit tester like part # PTW2993. Typically, vehicle manufacturers use specific-colored wires for certain functions, but you would have to test to make certain, as the color codes are not always reliable. You would then need to find out what function each of the wires on the trailer are. You could run a separate 12-volt battery to test the trailer lights. You would furnish...
    view full answer...
  • Tips for Identifying 4-Way Wiring Colors that Use Non-Standard Colors
    Your Dakota uses non-standard wire colors for the 4-way so your best option is going to be to test all of the the wires while applying the various taillight functions of your vehicle to verify you have the correct function of them all. For that you'd want a circuit tester like # PTW2993. I attached a video link to this page that shows how to do this as well. That said. MOST LIKELY the black wire is the ground since you said it's thicker than the other wires.
    view full answer...
  • Solution to Activate Reverse Lockout Solenoid of Surge Brake Trailer Being Towed with Front Hitch
    This is a really good question. Probably the best solution would be to wire a 5-way to the front of your truck like with the part # HM37908. Run the blue wire to your positive battery post and then the white to the ground and whenever it's plugged into your trailer the reverse lock out solenoid will activate and allow the trailer to move.
    view full answer...
  • Will a Trailer 4-Way Plug Into a Vehicle 5-Way Without Adapter
    Yes, you can plug a trailer side 4-way trailer connector part # 002402 into a vehicle side 5-way connector part # HM37908 without any adapters needed.
    view full answer...
  • Which Circuit Runs to Blue Wire of Trailer Wiring
    Your trailer wire that is blue would be for the trailer brakes so the truck blue wire that is labeled electric brakes would be the correct one to use. Not every trailer has the need for a reverse light circuit.
    view full answer...
  • Shortest 5-Way Flat Vehicle and Trailer Side Connectors
    The shortest pre-made 5-Way flat vehicle side connector that we have is 48 inches long, # HM47900. If you need the trailer side instead we have # HM47910 or # HM37918 which are 18 inches long.
    view full answer...
  • Should Trailer Running Light Circuit Run to Both Taillight Assemblies on a Trailer
    Most likely yes. The brown wire coming from the vehicle should be the running light circuit like you mentioned and the running light circuit of your trailer will most likely be a brown wire that also runs to the taillight housing on the trailer. The brown wire will need to go to both sides of the trailer's taillights to carry this circuit to both lights.
    view full answer...
    Image 1 for
  • Can a 4-Way Flat on a Truck Be Used with a Trailer 5-Way Flat without Connecting Extra Wires
    I recommend using the Adapter # 47515 or # 20036 and not connecting the extra blue wire to anything on the truck. On a 5-Way flat connector, the extra blue wire is normally for an electric reverse lockout which you find on a lot of boat trailers. The brakes on the trailer are probably hydraulic with a reverse lockout on the coupler. The blue wire sends power from a reverse light circuit to a solenoid on the coupler that does not allow fluid to pass through to the brakes when the vehicle...
    view full answer...


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Do you have a question about this Trailer Wiring?


Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Joshua S
Video by:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Cole B
Installed by:
Cole B
Employee Ryan G
Installed by:
Ryan G
Employee Alexander C
Written by:
Alexander C

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