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Roadmaster Automatic Battery Disconnect with Switch for Towed Vehicle w/ Supplemental Braking System

Roadmaster Automatic Battery Disconnect with Switch for Towed Vehicle w/ Supplemental Braking System

Item # RM-766
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Roadmaster Auto Battery Disconnect Accessories and Parts - RM-766
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Conveniently disconnect your battery so that your vehicle can be flat towed per manufacturer instructions. System with switch charges your towed car's battery during towing to prevent dead battery and maintain charge for accessories. 1-636-306-4830 to order Roadmaster accessories and parts part number RM-766 or order online at etrailer.com. Free expert support on all Roadmaster products. Guaranteed Lowest Price and Fastest Shipping for Roadmaster Automatic Battery Disconnect with Switch for Towed Vehicle w/ Supplemental Braking System. Accessories and Parts reviews from real customers.
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Roadmaster Accessories and Parts - RM-766

  • Tow Bar Wiring
  • Auto Battery Disconnect
  • Roadmaster

Conveniently disconnect your battery so that your vehicle can be flat towed per manufacturer instructions. System with switch charges your towed car's battery during towing to prevent dead battery and maintain charge for accessories.


Features:

  • Lets you easily disconnect your battery so that your vehicle can be towed behind your RV
    • Can only be used on vehicle on which battery must be disconnected for towing
    • Includes switch for installing in the towed vehicle
    • Consult your owner's manual
  • Eliminates inconvenience and the potential danger of pulling your battery cable
  • Operates with switch
  • Includes a corrosion-resistant, marine-grade solenoid with 200-amp constant duty and 600-amp surge
  • Works with almost any 12V battery
  • Comes pre-assembled for easy installation


Notes:

  • Disconnecting the battery, whether manually or with the Roadmaster automatic disconnect, will affect your vehicle's electronics. You will need to reset various electrical components in your vehicle following use of this product.
  • Not for use with diesel engine vehicles, due to the high compression ratio of diesels the engine can surge up to 10 times that of a gasoline engine at start up and can cause the solenoid to fail.
  • A charge line, (RM-156-25 - sold separately), is a good idea if you have a braking system that is using power from the towed vehicles battery while it is disconnected.


766 Road Master Automatic Battery Disconnect

Replaces 765

Installation Details RM-766 Installation instructions

This Product Fits The Following Vehicles





Customer Reviews

Roadmaster Automatic Battery Disconnect with Switch for Towed Vehicle w/ Supplemental Braking System - RM-766

Average Customer Rating:  4.8 out of 5 stars   (145 Customer Reviews)

Conveniently disconnect your battery so that your vehicle can be flat towed per manufacturer instructions. System with switch charges your towed car's battery during towing to prevent dead battery and maintain charge for accessories.

- RM-766
by:

This product works great for our 2018 Ford Explorer. It works perfectly for our application and allows us to easily disconnect the vehicle battery when we are preparing to tow the Explorer.



- RM-766
by:

The RM-766 is a solid piece of hardware and comes with absolutely everything required for the install, right down to the "Tow" and "Drive" stickers for the switch. I use it to disconnect the battery in my 2016 Ford Edge 3.5L AWD, to help make it flat towable behind my RV. It works great and I do not have to open the hood and mess with battery cables while travelling. I like it.


Comments
There have been absolutely zero problems with this switch so far. Works like a charm.
Herbert M - 07/13/2018



- RM-766
by:

I received the Roadmaster remote battery disconnect in a timely manner and had it installed in my 2016 Chevy Colorado by a local RV dealer. I used it for the first time this week and it worked like a charm. I didn't lose any of my preset radio stations or any other data that I know of. Pushing a button on the dash is a lot easier than disconnecting and reconnecting battery cables.


Comments
Still working just fine.
Robert M - 09/09/2017



- RM-766
by:

I have a 2014 Silverado that I wanted to tow with my RV. In order to tow GM calls for the battery to be disconnected. This was the only product that I fond that would do what I wanted. It is slightly over priced in my opinion but it does the job. I have attached it to my aftermarket air box and ran the switch under the hood release. This way I can use the remote to unlock the doors when I am ready to unhook.



- RM-766
by:

The battery disconnect installation instructions were clear and the installation went well in my 2018 Chevrolet Colorado ... in spite of the kit missing a few pieces like a second star washer for connecting the two battery cables and the second piece of protective tubing. I covered the exposed energized solenoid terminals with electrical tape to prevent an potential inadvertent short in the future when working under the hood. Works as designed so far.


Comments
I towed the Colorado from Maine to Arizona last winter and the battery disconnect worked well for the entire trip. It made preparing the truck for towing and driving very easy!
Mike - 07/01/2020


- RM-766
by:

The product was as advertised and the delivery was also as promised. The order staff was very helpful and knowledgeable about the product and which model to order. The tech support was also very helpful and seemed to know the product and exactly what steps to take for a successful installation.



- RM-766
by:

Love the ease of battery disconnection with this product. The electronics in my 2021 Silverado seem to hate being without power though, and the remote keyless entry is a little finicky for a few cycles after power is restored, by that’s a Chevrolet issue.



- RM-766
by:

LOVE IT!! Most of my other friends do not have the disconnect on their vehicles and have to deal with dead batteries and running their tow vehicle engines every couple of hours.



- RM-766
by:

making towing and keeping battery up, what could be better?



- RM-766
by:

missing on off button


Comments
I will have our Customer Service team reach out to you.
-- Etrailer Expert Jenny N - 06/03/2022


- RM-766
by:

Everything works amazing Thanks to all at etrailer



- RM-766
by:

Easy to install and did what it was supposed to do



- RM-766
by:

Would not respond to a phone call or answer a simple question. No more business with etrailer for me.



- RM-766
by:

I bought this product because to tow my GMC Canyon I have to disconnect the battery and I didn't want to have to get under the hood every time I hooked up and unhooked the vehicle. This product was easy to install, especially with the on-line video. The only mishap I had was the video said to use a 1/4" drill bit to drill pilot holes for the two sheet metal screws that mount the solenoid onto the inside fender. This makes the holes the same diameter as the screw threads and they won't bite. I had to re-drill new holes with a slightly smaller drill bit. The kit did include two 1/4" nuts and bolts to use instead if you access with your fingers to the backside for placement of the nut. I could use the forward hole for the nut/bolt but the rear hole I had to use the sheetmetal screw as it is a double panel. I wasn't comfortable with the two positive terminals on the solenoid being in a location, where when working in the engine compartment, tools can accidentally touch the positive terminal and the solenoid housing and create a spark. I fashioned a piece of inner tube cut in a rectangle and mounting it above the solenoid onto the sidewall, cut a hole for the top plastic cone to stick thru and it now lays over the solenoid covering the terminals enough where accidental contact is minimized.



- RM-766
by:

I gave each and every one of the items I purchased a 5star rating because they each have contributed greatly to my confidence and sense of security about full-time RVing in my Class C rv towing my little car behind. Each product has been well made and thought out and the service from etrailer has been great....from price to shipping and packaging. I couldn't be more pleased with everything. Job well done. Thank you.



- RM-766
by:

i've been towing my gmc canyon for the past year .we have gone to ky., mn.,fl.,and mo. with no problems. the towing package i bought was and easy install and took just a few hours by following the instructions. it was money well spent.


Comments
great!
lupe v - 04/04/2021


- RM-766
by:

The instructions were good and they were detailed. The product works as advertised. The button is made so it would be difficult for it to be pushed accidently in most places where it might be installed. The greatest difficulty for me was getting nuts on the mounting bolts for the solenoid. Also, my 2014 Jeep Wrangler had three wires attached to the positive battery post so it was not that straight forward attaching all three to the battery cable. A larger diameter piece of shrink wrap would have helped in this case.



- RM-766
by:

Haven’t put it on yet, showed up on time and in good condition, have your e mail and phone no. So will communicate when it is installed tks



- RM-766
by:

This product is much improved over the video that I watched prior to ordering the product. It does not require 3 wires, but 2 wires. The wires are already connected to the solenoid so there is no need to strip wires and clamp on connectors. The switch is a simple push on-off so no stickers are needed to be placed inside the car. Overall it was very simple to install and works great. Only draw back was getting the 2 wires through the firewall. The video showing how to accomplish that task could have been significantly better. 5 second mention of rubber grommet was not enough to help accomplish this task. Bottomline. GREAT product.



- RM-766
by:

Great company. Always responsive to the customer's needs. Had a needed part sent overnight. Arrived ib 16vhours after order was placed. Allowed for us to begin our journey as fulltime RVers as scheduled.



- RM-766
by:

Installation and function have been without issue.



- RM-766
by:

Easy to install. My wife gets our tow vehicle ready to roll. She would not disconnect the battery cable. Now all it takes is a flip of the switch! Happy with this battery disconnect product.


Comments
Our battery disconnect works perfectly every time. Makes preparation for towing much easier
Mike H - 08/24/2018



- RM-766
by:

It was easy to install.



- RM-766
by:

Received on time and in good condition.



- RM-766
by:

I have ordered many products from etrailer and their customer service is 12 on a scale of 1 to 10. I ordered my products on the weekend and they were delivered on a Wed. I also later found cheaper prices on a few of the items and submitted the info for the 110% lower price guarantee and received the refund within a few hours. These folks are just plain great!


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Ask the Experts about this Roadmaster Accessories and Parts



  • Key Position for Flat Towing a 2014 Jeep Wrangler Sahara
    Different vehicles have different requirements and procedures for flat towing. In order for your 2014 Jeep Wrangler Sahara to be flat towed, and really any vehicle, the steering wheel has to be unlocked which requires a certain key position. An automatic battery disconnect, # RM-766, is not a requirement to flat tow your Jeep. But if using a supplemental braking system, required in most states by law, and if it requires 12 volt power, you could install a 12 volt outlet kit, # RM-9332....
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  • Does Installation of the Roadmater RM-765 Auto Battery Disconnect Charge the 2008 Honda CR-V Battery
    The Roadmaster Auto Battery Disconnect, item # RM-766, includes all of the parts needed for installation on your 2008 Honda CR-V, and supplies a trickle charge from the towing vehicle to the towed vehicle battery when properly installed. You will not need to remove the fuse for flat towing if the battery disconnect is installed on your vehicle.
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  • Installation of Roadmaster Auto Battery Disconnect # RM-766 on 2009 Hummer H2 With 5-Way Connector
    Since the battery must be disconnected when flat towing your 2009 Hummer H2 an option is to use the Roadmaster Auto Battery Disconnect, part #RM-766. The disconnect is activated by the taillight circuit from the tow vehicle. When the tow vehicle taillights are on, the solenoid is activated and the Hummer battery is automatically disconnected. The power from the taillight circuit that is not needed to keep the solenoid open is then routed to the Hummer battery helping to maintain the charge...
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  • Best Place to Mount Automatic Battery Disconnect from RoadMaster Part RM-766
    The most common place that they are mounted is on the fender or on the firewall, depending on battery location. The heavy gauge wire leads for the battery are long enough to allow flexibility as far as mounting location. It is not an extremely complex operation, and the simpler the operation, the less problems. We have not heard of any problems with the units we sold so far.
    view full answer...
  • Why Does the Battery Need to be Disconnected to Flat Tow a Ford Edge
    Generally speaking, when the owner's manual calls for the battery to be disconnected it is because certain features need to be disabled so they do not draw power from the battery and drain it. If you need to know exactly which feature(s) that is then you would need to contact your local dealer as I would not be able to say for certain what those feature(s) are. I also cannot recommend going against the owner's manual in any way which includes not disconnecting the battery. If you would...
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  • Can Roadmaster Battery Disconnect Kit # RM-766 Install on 2014 Jeep Wrangler Unlimited
    The Roadmaster Automatic Battery Disconnect with Switch for Towed Vehicle w/ Supplemental Braking System # RM-766 that you referenced is designed to replace the older RM-765 that you also mentioned. The # RM-766 will fit your 2014 Wrangler and work well but we do not have a way to replace just the solenoid of the 765 to be a 766.
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  • Why Remove the Negative Battery Terminal First When Installing a Automatic Battery Disconnect
    By removing the negative battery cable you are disconnecting the battery from the chassis of your vehicle. If you begin to remove the positive side before the negative and your wrench would make contact with any part of the vehicle, then you could cause a short in the system. This could in turn blow fuses and relays or even damage some of the sensitive electronics on your 2016 Chevrolet Tahoe. Roadmaster specifies that the Automatic Battery Disconnect, # RM-766, be installed on the positive...
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  • Does Battery Have to be Disconnected to Flat Tow a 2019 Chevrolet Silverado 1500
    Yes, the battery does need to be disconnected to flat tow a 2019 Chevy Silverado 1500. To make it easier I recommend adding the Roadmaster Automatic Battery Disconnect with Switch # RM-766. I have added a link to a video review and installation for you to check out as well.
    view full answer...
  • Battery Charge Wire Recommendation for 2014 Jeep Wrangler When Flat Towing
    For the most part yes. A charge wire from your tow vehicle to your towed vehicle will help prevent battery drain as you are on the highway. For that we have the part # RM-766 which is designed to charge the battery and automatically disconnect it when flat towing.
    view full answer...
  • Will Battery Disconnect RM-765 Work On 2014 Smart Car?
    Based on my research, it is required that you disconnect your battery during towing. The Automatic Battery Disconnect For Towed Vehicles, Item # RM-766, is what you need. Consult your owner's manual to confirm what you need to do for your Smart car. If you need anything else to flat tow your Smart car then let me know. Links to additional information attached.
    view full answer...
  • Recommended Battery Disconnecting Switch For 2016 Ford Edge
    You can run a hot line from your motorhome to your battery. It will maintain your battery to an extent but hard to know what the power draw is on your battery and whether that hot lead would charge enough to still keep your battery charged enought to start following your trip. Your vehicle relays and fuses will protect your computer and electronics. I recommend the Roadmaster Automatic Battery Disconnect with Switch for Towed Vehicle w/ Supplemental Braking System, # RM-766. This will...
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  • Using Roadmaster Automatic Battery Disconnect RM-766 When Flat Towing 2017 Ford Explorer
    Some vehicles require disconnecting the negative battery cable when flat towing them to prevent battery drain. If you have installed the Roadmaster Automatic Battery Disconnect # RM-766 you will not need to do this since this item includes a switch to select either Tow or Drive modes. It will deliver a trickle charge to your toad's battery. Please refer to the linked installation video showing another Ford vehicle.
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  • Recommended Battery Disconnect For 2015 Ford Edge Titanium
    I confirmed with Roadmaster that # RM-766 is the correct part to disconnect the battery on your 2015 Ford Edge Titanium and I do recommend this part for an easy way to protect your vehicle without needing to move wires each time. This disconnect makes it as easy as a flip of the switch on your dash to make your vehicle drivable or towable. I've attached an installation video of this product for your convenience.
    view full answer...
  • Installing Roadmaster Automatic Battery Disconnect with Switch on 2015 Chevrolet Silverado 1500
    When installing the solenoid for the Roadmaster Automatic Battery Disconnect with Switch # RM-766 on your Chevrolet Silverado, you will just want to find a spot under the hood, within reach of the battery. Also keep in mind that the solenoid will need to be grounded, either by attaching it to a metal surface or by using the included white ground wire. One red cable, which will be labeled "battery post" coming from the solenoid will go to the positive battery post in your vehicle. The...
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  • Installing Roadmaster Automatic Battery Disconnect with Switch on 2016 Chevrolet Colorado
    According to the online owner's manual for the 2016 Chevrolet Colorado, you will need to disconnect the negative battery cable at the battery and secure the nut and bolt before flat towing the truck. It states that failure to do this may cause damage to the vehicle. When installing the Roadmaster Automatic Battery Disconnect with Switch # RM-766 referenced in your question, you will first follow the vehicle manufacturer's instructions to disconnect the negative battery cable. Then from...
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  • Should Roadmaster Automatic Battery Disconnect be Installed on Positive or Negative Side of Battery
    The Roadmaster Automatic Battery Disconnect, part # RM-766, does need to be installed on the positive side of the battery, even on vehicles that state to disconnect the negative cable. Roadmaster released a tech bulletin about this which is probably what you read. The reason is because if you use the disconnect on the negative side you'll lose your towed vehicle's main ground to the chassis. This means that all of the accessories that need to operate on the toad must be grounded through...
    view full answer...
  • Can Roadmaster Automatic Battery Disconnect be Used on Positive Terminal of 2014 Jeep Wrangler
    The Roadmaster Automatic Battery Disconnect # RM-766 referenced in your question can absolutely be installed on your 2014 Jeep Wrangler Unlimited but it does need to be installed on the positive battery terminal. As you mentioned, the manual for your Jeep recommends disconnecting the negative terminal when flat towing, which provides a bit of a contradiction with the instructions for the Roadmaster Battery Disconnect. This recommendation is present in a lot of vehicle owner's manuals...
    view full answer...
  • Disconnecting the Battery of 2016 Ford Edge For Towing Behind RV
    I'd recommend using a Roadmaster Automatic Battery Disconnect, part # RM-766. The disconnect would allow you to 'disconnect' the battery with a flip of a switch. When the battery is disconnected, the taillight circuit from the RV will maintain the battery in the towed vehicle (you'll need to leave the running lights in the RV on for this to happen). The owner's manual specifically states that the battery needs to be disconnected, I wouldn't recommend doing anything else other than physically...
    view full answer...
  • Will the Brake Buddy Battery Maintainer work with Battery Disconnect RM-766
    The Battery Disconnect part # RM-766 installs on the positive battery wire so that when activated all power is cut for the vehicle. See attached chart. What you would need to do is install the # RM-766 after the connection you have for your Brake Buddy so that it can still draw voltage when needed even if the # RM-766 is activated.
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  • Recommended Battery Disconnect For 2015 GMC Yukon Being Flat Towed
    When flat-towing your Yukon, GM does recommend you disconnect the battery which would then allow you to be able to put the key in ACC mode and allow the steering to turn without locking up. Since the ACC mode is the only method available I recommend a battery disconnect like the Roadmaster Automatic Battery Disconnect for Towed Vehicles, part # RM-766. This automatically disconnects the battery in your Yukon when the motorhome lights are turned on and saves you time with physically disconnecting...
    view full answer...
  • Using Roadmaster Automatic Battery Disconnect # RM-765 When Flat Towing 2011 Jeep Wrangler
    First and foremost, if Jeep requires the battery to be disconnected while flat towing, you must follow these instructions in order to prevent damage to your vehicle. The main reason for disconnecting the negative battery cable when flat towing is to prevent the battery from draining. When you flat tow your Wrangler, the ignition must be left in the ACC position. This would leave certain electronic components on that could drain the battery. The benefits of using the Roadmaster Automatic...
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  • Disconnecting Battery in 2015 Chevy Colorado When Flat Towing
    The main reason that the battery must be disconnected when flat towing is to prevent the battery from draining. When flat towing your 2015 Chevy Colorado, the key must be left in the (II) position. This would leave some of the electrical components on and drain the battery. To eliminate the hassle of having to disconnect your battery each time you want to flat tow, I recommend installing the Roadmaster Automatic Battery Disconnect, part # RM-766. The automatic battery disconnect is activated...
    view full answer...
  • Will Adding the Roadmaster Automatic Battery Disconnect on 2018 Ford Focus Void Warranty?
    The Roadmaster Automatic Battery Disconnect with Switch for Towed Vehicle w/ Supplemental Braking System # RM-766 will not violate your vehicle warranty according to the Magnuson-Moss Warranty Act because no damage will be caused as a result of adding this part, but it does make it possible to flat tow your 2018 Ford Focus without disconnecting the battery. The idea is to cut the power supply to the vehicle components when the switch is flipped so it will protect your vehicle from draining...
    view full answer...
  • Is Brake Lite Relay Needed When Flat Towing Vehicle with Battery Disconnect
    If you disconnect the battery of your vehicle with the disconnect kit part # RM-766 you actually wouldn't need a brake lite relay. Reason being that when the battery is disconnected the vehicle wouldn't be able to power the stoplights.
    view full answer...


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