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Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Trailer End - 18" Long

Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Trailer End - 18" Long

Item # HM37918
Retail:$14.99
Our Price: $8.05
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Trailer Wiring
Shipping Weight: 0.13 lbs
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Use this universal, splice-in wiring harness to connect your trailer to your tow vehicle. 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 - Trailer End - 18" Long part number HM37918 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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Hopkins Trailer Wiring - HM37918

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

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


Features:

  • 5-Way flat trailer-end connector plugs into the connector on your vehicle 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: 18"
  • 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


37918 Hopkins 5-Way Flat Connector - Trailer End - 1-1/2'

Installation Details HM37918 Installation instructions



Video of Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Trailer End - 18" Long

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




Video Transcript for Hopkins 5-Pole Flat Trailer Connector Wiring Harness Installation

Hey everybody, Ryan here at etrailer. Today we're gonna be checking out and showing you how to hook up the Hopkins five way trailer connector in. So what this five way is going to do is give you your basic functions. Right So you'll have your brake lights, your turn signals and your taillights but it's also gonna have another function. That's what this blue wire is here. That's gonna be for your reverse lights.

So there's a few instances on where this connector end would come in handy. If your trailer already has a setup like this and maybe the connector's beat up you can pick this up, you know, cut a portion of your existing wiring off and connect this into it. That way everything's new and fresh, or you can, I guess you could call it, upgrade from your traditional style four way flat connector here. And that's what we did here today. So on our boat trailer what we're doing is adding disc brakes and when you add disc brakes to a boat trailer or brakes for that matter, you're gonna have a surge type actuator here in the coupler.

And depending on what one you have some of these have an electric reverse lockout. And so what what will happen whenever the reverse light signal goes into here, it won't lock up the brakes and it'll let us allow us to back up. And so that's what we did. We got rid of our four way and hooked this one up, that way we can take our reverse signal that's gonna be coming from our towed vehicle or from our truck, It'll go into here and go into our reverse lockout solenoid whenever we're backing up or what some people do as well is, on my own smaller utility trailers and things like that, some people like to put reverse lights, you know, when they're backing up to the work site or whatever the case may be, and you could end up, you know, hooking up your reverse lights to this signal here and granted it's not gonna put out a ton of amperage but, you know, if you got a couple of led lights it's gonna be more than enough and that will work. So a few different applications for this, you know, I'm sure people use 'em for other things, too.

Those are just kind of things that come to my mind and something I wanna mention just since it's a five way, you can still use a, a four way flat, so let's say if your vehicle only has a four way or let's say if you get in a pinch, you need to borrow someone's car or something, you can still plug a four way into this. Right You just wont utilize that particular circuit. On a trailer like ours, probably not a good idea 'cause of this but if it's a utility trailer and it's, you're just using it for reverse lights, you know, it's not critical but just wanted to mention that, that way, you know, you kind of know what you need to do with your vehicle side. So I do wanna mention, you know, you're probably thinking what do I need to do on my vehicle side for this to work So let's just say, for example, if your tow vehicle only has a seven way round type trailer connector plug on on the back bumper or whatever, obviously this aint gonna plug right into it. So that's where something like this would come into play.

So this is essentially just an adapter and that end would plug into your vehicle seven way. And then it just turns into a five way flat connector. That way you can just plug that right in get everything that way. So pretty straight forward. Or let's say if your vehicle only has a four-way flat type connector on it, and you obviously want to use the reverse light function, there's vehicle ends as well. So you can actually convert your existing four-way flat connector on your car or your truck to one of these and be able to plug everything in and have all the functions actually work. The harness is going to be 18 inches long. So you're definitely gonna have some wires to work with in terms of that, depending on what you're doing you may need to extend some of 'em or kind of just depends on your existing trailer wiring, what's a, what's to work with there. And I do wanna mention, you know, it would be nice if they gave you a dust cover for this, obviously trailers sit outside a lot. It'd be nice to get this protected but if that's something you're interested in you can actually pick one up. It's pretty cool. It'll Mount to your trailer and then when you're done using it, you know, you can just plug it in there. So pretty cool actually, and to actually get this installed you know, it's gonna be similar for most people. We'll do it here in a moment and just kind of hopefully get you going in the right direction. But you know, you are gonna need a few things. I use some heat shrink butt connectors and a ring terminal. And then, you know, if you want to get wire loom and stuff you can always pick that up to but that's really just gonna be up to you. But if you'd like to see how we hook this up feel free to follow along. We'll go ahead and do that now. As far as the install goes, you know, everything's gonna be pretty much about the same. It's just really gonna depend on your particular application. If you already have a five way that's just all beat up and chewed up, you know, it'd be a direct replacement essentially. What we're doing is actually upgrading from our four way and that's because on our boat trailer here we're adding brakes and putting a different actuator up here which needs a reverse light circuit. So that's, that's what we're doing, doing here. So like I said, generally speaking, you know, it's five wires, they gotta be hooked up. So to begin ours though, what we're gonna do is get rid of our four way wiring here. So I'm gonna try to save as much wire as I can and I'm just going to, you know, cut these, cut these ends off. And since I'm adding a new coupler up here, it's a lot bulkier. I think I'm going to relocate this wire down below the trailer. So once I do that, I'll show you it and then we can actually start to get this hooked up. So I dropped our wired on through the bottom of the frame. Now there's already hole there and just makes more sense with the setup we're getting ready to do. I did strip back the ends of the insulation on these wires to kind of prep them. And we can do our actual five way now. So with these four wires, you will have to split 'em. So just carefully kind of cut in between 'em. We'll peel 'em back a little ways. Like that and then I'm gonna strip back all the ends here. Let's do this one at a time. Once you strip it back, give it a twist and then take a heat shrink butt connector, place that over the end and crimp it down. I'll do the same thing for our remaining ends here. So here's what all the ends look like and now we can get ready to hook 'em up. So your blue ones could be for your reverse light circuit. Green will be right turn, yellow will be left turn. Brown will be taillights and white will be your ground. And that essentially holds true for the majority of trailer wiring. So ours is set up a little different. So we have green for right, yellow for left and then these two browns are for our taillights on each side. You might have two wires like this, you might have one, but with these, our taillight ones here, I'm just gonna twist them together and that'll work just fine. And now we can start to hook these up color for color. So there's some of our connections made and with these being heat shrinks, I'm gonna take a heat source and seal up the ends. As far as the blue wire and our white ground wire, what I did with the white one, I just added a couple foot of wire to it 'cause I'm not real sure where I'm gonna ground this just yet. And the blue wire will get hooked to your reverse lights circuit, whether it be, you know, for utility lights, some sort of reverse lights on your trailer or in our case, it's gonna go to the actuator on our coupler here on our boat trailer for the reverse lockout. So before I worry about getting these hooked up I'd like to get our coupler on, that way we know kind of what we have to work with and we can get everything all done at once. With this all bolted down, we can hook up the wiring coming out of it. So there will be two wires. One of 'em will be ground. The other one will go to the reverse light signal. Doesn't matter which wire, you know, either end as long as you're eventually both hooked up. So kinda got this one ready, crimped on a butt connector, and I'll just use that one for our reverse light wire coming from our five way wiring. It's usually blue. So to hook these up, strip back the insulation, give it a good twist. Put that bare end of the wire in there and crimp it down. And since this is a heat shrink type connector I'm gonna grab my heat source real quick and seal up the ends. For our, the other wire here, I guess that's gonna be ground. I need to hook up the ground for our new five-way wiring anyway so I just twisted them together and we'll just share a ground, kind of reduce or eliminate one extra unnecessary connection if that makes sense. So twist them together. My ring terminal isn't a heat shrink style so I have a piece of tubing here, heat shrink tubing that I'm gonna use. I'll slide that on first, followed by our ring terminal. Crimp it down. Slide my tubing over the top. And once I heat shrink this we can ground it to the frame. To ground this I just have a self tapping screw. We're gonna go to our frame and just get it secured. So I went ahead, got our white wire and our blue wire hooked up. I did have to extend the blue wire just like we did the white one but our white wire goes to ground. So pretty straightforward. I just crimped on a ring terminal, screwed it to our frame with a self tapping screw. And the blue wire in our case is going to our actuator coupler here for the reverse lockout. This might vary a little bit for yours. If you have a setup like this, this is what it'll go to. Or like I said, if you have some type of other accessory on your trailer, whatever the case may be, you'd get that hooked up as well. But really, beside from kind of taping everything up and getting it clean, that's really about it. If you have the rest of your lighting system and whatnot hooked up it's probably not a bad idea to test this too to make sure all of our connections are good. So I plugged into a test box. You can use your tow vehicle too. Just keep in mind if it has any issues with it, might translate over to the trailer side but we'll try our taillights. Our left turn signal. Our right turn signal and our brake lights. So now that we verified everything works I simply just taped up all of our connections and put on some wire loom just to help kind of clean up our install look, but with that done, that'll finish up our look at and our installation of the Hopkins five-way trailer connector..

Customer Satisfaction Score:


Customer Reviews

Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Trailer End - 18" Long - HM37918

Average Customer Rating:  4.8 out of 5 stars   (24 Customer Reviews)

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

by:

The whole staff at etrailer bent over backwards to make sure I was satisfied with the installation of brakes on my trailer. Have made several purchases from them always satisfied with parts and service. Special credit to Jamie great to deal with. Answered all my questions and was very knowledgeable.



by:

I purchased trailer lighting for my flatbed trailer. Very satisfied with the parts and the service I received. Will use you again when the need arises.



by:

This is great for hooking tailgate light bars with back up lights



by:

My order came on time and the product is great. The Tech support was great this is my new go to place for all my parts now.



by:

I have used etrailer.com for multiple purchases for my boat trailer and am quite pleased with their customer service.



by:

The harness works great. I've never had a problem with anything I've ordered from you folks.



by:

I was moor impressed with the customer services I received from Dena W.
She was very professional and extremely helpful through this hole process. Dena stayed in constant communication with me through everything that happened with this order. She gets 5 Stars



by:

Product was everything as advertised, and with great quality. Way to build a long term customer base!



by:

Works great and is continuing to work after a year.



by:

itme was easy to order online, and i got what i ordered and on time. Good product.



by:

Good communication and delivery I would buy from again



by:

Works great



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Easy to install and last forever.



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Good



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thanks



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See what our Experts say about this Hopkins Trailer Wiring

  • Replacement for 5-Way Trailer Connector with 9 Wires
    For a replacement 5-way trailer connector, I recommend the Hopkins Wiring Harness with 5-Pole Flat Trailer Connector part # HM37918. In regards to installation, you really need to test the wires for function to determine their purpose but if I had to guess I would say the red is for the reverse lockout or running lights, green for right stop/turn, yellow for left stop/turn, and white for ground. The extra wires will just be combined into once but you should verify each of the functions prior.
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  • Troubleshooting Trailer Lights Not Working with Running Lights Turned On
    According to our research you either have an insufficient ground, or you have way too many running lights on your trailer. I recommend making sure your all of your wiring connections are nice and solid and that the grounds are securely connected to a clean, bare-metal surface. If that doesn't work then try disconnecting one tail light at a time to see if that reduces the amount of power being pulled to the tail lights enough that the other lights work correctly.
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  • 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.
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  • How To Hook Up Trailer Lights on a Honda Goldwing Motorcycle
    It sounds like you may be trying to plug a motorcycle with separate tail light circuits into a trailer with combined tail light circuits or vice versa. If that is the case then you will need to use a separate to combined converter box. For example, if the motorcycle has separate tail light circuits and the trailer has combined tail light circuits then you will need part # RM-732 but if the motorcycle has combined tail light circuits and the trailer has separate tail light circuits then...
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  • How To Convert 6-Pin Round on Motorcycle Trailer to 5-Way Flat
    The majority of motorcycle trailers use separate lighting therefore in order to convert to a 5-way which uses combined lighting you'll need a converter, the Curt 2 to 3 Wire Tail Light Converter part # C56196. Then you'll also need the Hopkins Wiring Harness part # HM37918 but that's all.
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  • How To Add Reverse Lights to Trailer with 4-Way and Vehicle with 7-Way
    The Hopkins Wiring Harness part # HM37918 can be used to install a five way on the trailer which is capable of carrying the reverse light circuit, you would indeed need to run a wire from the reverse lights to the trailer connector. Then you'd need an adapter for the tow vehicle, the Adapter 7 Pole to 5 Pole Flat part # A75TB is for 7-ways. I have attached our selection of reverse lights below as well.
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  • Availability Of a 5-Way Flat Extension 12" to 18" Long
    I do have a solution for you as we do not have any 5-way flat extensions. You can cut and splice the Vehicle End # HM47900 to the Trailer End # HM47910 at the length you need. I recommend making the connections with Heat Shrink But Connectors # DW05744-5 to help keep moisture away from the connections.
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  • How to Find Correct Wiring For Hooking up Hopkins 5 Flat HM37918
    I can help you figure out how to determine which wires to hook up a 5-flat like the Hopkins # HM37918, though we don't have any way to know the functions of your trailer's wiring, because there is no universal color code, as helpful as that might be. What you need to do is either trace the wires back to their lights if possible, or test the wires for function using a charged 12 volt battery and a jumper cable, applying 12 volts to each wire. This is going to tell you what their functions...
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  • Solution for Replacement Cylinder for Discontinued Atwood 82543 Brake Actuator
    The Atwood TA82543 on your 1995 boat trailer has been discontinued. This means that replacement parts like the master cylinder are no longer available. The only solution is to replace the brake actuator with one like the # T43397007K you were looking at. This is a good replacement option especially if you need the multi-fit for different balls. This brake actuator does not have a lockout feature so if you need one you will have to add the # T4748800. You will also need to add a 5-way...
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  • Best Replacement for a Atwood Surge Brake Actuator 85778
    The best replacement option we offer for an Atwood Surge Brake Actuator 85778 is the Demco Hydraulic Brake Actuator part # DM62VR. It has the same ball size, offers a bolt-on install, and has a greater capacity. The only difference is it has an electric lockout as opposed to a manual one which aren't really used anymore. Therefore, you'll have to get setup with a 5-way for the trailer and truck. This can be done using part # HM37918 and part # C57187.
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  • Will the Titan Brake Actuator T4749600 Allow for Reversing Uphill
    The Titan Brake Actuator part # T4749600 does not come with a lockout so in order to reverse you'll need to install a lockout solenoid, the Replacement Solenoid Valve for Titan Brake Actuators with Reverse Lockouts part # T4748800. This would also require a 5-way trailer connector so you'll also need the Curt Trailer Connector Adapter part # C57187 and Hopkins Wiring Harness part # HM37918. That said, in regards to uphill reversing you'll need to do so very slowly as left over fluid in...
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  • Recommended Replacement for Atwood 82543 Brake Actuator
    The Demco Hydraulic Brake Actuator item # DM72VR, you were looking at, is the best option to replace an Atwood 82543. This coupler features a simple-to-use latching mechanism known as the EZ-Latch. With this mechanism, hooking up is as easy as dropping the coupler over your trailer hitch ball. This actuator does not come with any sort of reverse lockout feature. To reverse without the brakes locking up you will need to add an electric solenoid like item # T4748800. It's an electric lockout...
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  • Converter Box for Separating Out Combined Trailer Wiring Circuits
    We do have converters that are designed to take a combined stop/turn signal circuit and separate them out with the converter part # 118158. You'd wire the combined circuits to the input side of the box and on the output side you'd have separate circuits. You'd need more than 4-way wiring though. We have a 5-way with a 60 inch lead with the part # C58531. Then for a matching connector for other side you'd want the part # HM37918.
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  • How to Attach a Motorcycle Trailer with 5-Way to Vehicle with 4-Way
    If your motorcycle trailer has a 5-way flat then you will need to use the Curt Trailer Connector Adapter part # C57187 in order to attach it to your tow vehicle. However, if your motorcycle trailer has a 5-way round then you will need to remove this and install a 5-way flat, the Hopkins Wiring Harness with 5-Pole Flat Trailer Connector part # HM37918 as there are no adapters to go from a 5-way round to a 4-way flat. If none of the trailer lights work once you have the correct adapter then...
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  • How To Attach Trailer with Six Way Using Vehicle with Four Way
    In order to reverse a trailer with surge brakes you most likely need a lockout feature. The most common type of lockout feature is electric which would seem to be what you have due to the type of trailer connector installed. I do have an option for you but the four pin trailer connector on the vehicle does not contain a reverse circuit which is needed for the electric lockout. I have attached a few options below. Option 1: The first option would be to remove the six way on the boat trailer...
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  • Parts Needed To Properly Transfer Light Signals From A Honda Goldwing To A Motorcycle Trailer
    While there currently isn't an adapter to easily go from the 4-pole connector on your trailer to the 5-pole connector on your Goldwing I do still have a solution for you. You'll need to cut off the 4-pole connector on the trailer and splice in a 5-pole connector like part # HM37918. You can just cap off the reverse light wire with some electrical tape and if you ever wanted to install reverse lights on the trailer you could then run a line off it it. I recommend using some heat shrink butt...
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  • Best Replacement for Atwood 82543 Brake Actuator
    The Demco Hydraulic Brake Actuator part # DM72VR is a great option to replace an Atwood 82543. That said, it does not come with any sort of reverse lockout feature therefore in order to reverse without the brakes locking up you will either need to add an electric solenoid such as the Replacement Solenoid Valve part # T4748800 or switch to free backing braking assemblies. The latter is more expensive and time consuming. Therefore, I recommend the former but you also need to switch to a 5-way...
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  • Jacketed 5 Pole Trailer Wiring
    The best I can do for you is recommend getting the Hopkins Wiring Harness # HM37918 and some wire loom # 7509-1. The only jacketed wiring we have are 4 pole connectors. The wiring harness is plenty long so you can just cut off the excess. If you only need exactly 10ft you can get the 10ft roll of loom # 7509-10. One thing you could do is get this # DW04906-1 jacketed 6-wire which you can buy per foot. You won't use the 6th wire so just cap it off if need be.
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  • Correct Demco Hydraulic Trailer Brake Actuator For Use with Disc Brakes
    For starters, the Demco Hydraulic Trailer Brake Actuator part # DM72VR is for drum brakes only and it sounds like you have disc brakes. Therefore, the correct Demco Hydraulic Trailer Brake Actuator for use with disc brakes is part # DM62VR which does come with a reverse lockout feature. In order to use this you will also need a new trailer connector, the Hopkins Wiring Harness part # HM37918 and an adapter, the Adapter 4-Pole to 5-Pole Trailer Wiring Adapter part # 47515. The Demco Hydraulic...
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  • Can 12 Volt Power Be Run With a 4 Flat Trailer Plug?
    Typically a 4 Flat plug will not have a lead that goes to a battery as the White wire is the Ground, The Yellow is Left Turn/Brake, Green in Right Turn/Brake, and Brown is Running Lights. If you were using this for a different application, you can technically use any of the wires to run to the battery, but I do recommend using the White as the Ground as this is the standard. If you are using this as trailer wiring, I recommend going a different way. The Deka Jacketed 6-Wire # DW04906-1...
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  • Options to Replace Atwood 82543 Hydraulic Brake Actuator
    The Demco Hydraulic Brake Actuator part # DM72VR is for drum brakes which is what you need to replace an Atwood 82543. The other options you're inquiring about are for disc brakes which won't work. In short, there are tons of different versions of the Demco Hydraulic Brake Actuator each with different features such as drum/disc brake compatibility, weight capacity, ball size, lockout type etc. The correct one for the Atwood 82543 is listed above. In order to reverse without the brakes...
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  • How to Use the Lockout on the Titan Brake Actuator with Manual Lockout Part # T63FR
    In order to engage the reverse lockout on the Titan Brake Actuator with Manual Lockout part # T63FR you will need to insert the lockout tool which should be included, into the channel directly behind the coupler. I have pointed this channel out for you as well as the tool that is needed. If you don't have this tool then you will need to obtain this from the manufacturer. However, the other option you have is to add an electric lockout that will work when you place the tow vehicle into...
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    Image 1 for Image 2 for
  • How To Add Reverse Lockout To Demco Hydraulic Trailer Brake Actuator 8605001
    To add reverse lockout to the Demco Hydraulic Trailer Brake Actuator - Drum Brakes - Zinc Plated - 2" Ball - 6,000 lbs 8605001 you purchased you will need the Reverse Lockout Solenoid Kit for Demco DA66B Hydraulic Brake Actuators - Non-Bypass # DM5836. One wire from the # DM5836 will get grounded, and the other will get attached to a 5-way connector on your trailer. If you do not have a 5-way connector on your trailer currently you will need to add one using # HM37918. Once the trailer...
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  • Replacement for Atwood 61101 Brake Actuator
    The Demco Hydraulic Trailer Brake Actuator part # DM72VR should be a direct replacement for the Atwood 61101 Brake Actuator that you have now. This newest updated it rated at 7K instead of 6K. This is a bolt on option that mounts on 3" centers. The review you are referring to, the customer did indeed weld the brake actuator to his tongue but this is not required for installation because it is a bolt-on actuator. Unfortunately, we do no offer a bolt-on brake actuator for drum brakes with...
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    Image 1 for

Do you have a question about this Trailer Wiring?


Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
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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