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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. Call 800-298-8924 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:  4.9 out of 5 stars   (70 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:

897386



- RM-766
by:

874610



- RM-766
by:

Wow!!! So very impressed with this company!!’ Haley helped me by phone make sure everything I ordered was right for my RV and Smartcar (tow bar, base plate, battery shutoff and wiring). It came quick and the quality of the products (Blue Ox) are outstanding. Highly recommend this company!! Thank you for helping me!! 887217



- RM-766
by: 08/29/2020

870775



- RM-766
by:

This works great...!! 861758



- RM-766
by: 08/06/2020

Product works great .... great customer service 857153



- RM-766
by:

Got excellent help from Tara to select precisely the right part for wiring my car as a towed vehicle. 856860



- RM-766
by:

Dry good products 850890



- RM-766
by:

Sold and installed by etrailer. This battery cutout was necessary to tow our Jeep. It works as advertised and the installation work done by etrailer is neat and tidy. Top marks! 845453



- RM-766
by:

product was exactly as advertised and easy to install. it was just what i was looking for 844559



- RM-766
by:

Went right in. Had to hunt for a good mounting location The install video made the job a snap 844491



- RM-766
by:

I have installed this battery disconnect on a 2017 Ford Focus, 2016 Ford Fiesta and an going to install in a 2014 Jeep Cherokee Trailhawk. I was having some electrical issues before I installed... but good to go now... no issues to report. Customer service was very knowledgeable and helpful 828392



- RM-766
by:

This thing works PERFECT. thanks for the fast shipping as well A+ job guys! 815460



- RM-766
by:

Installed in my 2016 Chevrolet Colorado with the 2.8 diesel. Worked great. I installed it in a way that if it failed, I could quickly bypass, but it hasn't failed. Utilized it 5 or 6 times last summer. Haven't had to use it since, but hope to use it again soon. Definitely recommend for tow vehicles. 808432



- RM-766
by:

The items I ordered which are to complete the setup for my Jeep Toad arrived in a timely manner and were exactly what I needed. I have not had the opportunity to install yet but I don’t anticipate any issues as I have reviewed the instructions. Tammie was great to deal with and was very knowledgeable. This is not my first dealings with etrailer and won’t be the last. Great service and knowledgeable. Thanks. Keller Texas. Don’t have any pics yet. 811455



- RM-766
by:

Everything fit and working great. Install was pretty straight forward. 802642



- RM-766
by:

Everything fit and working great. Install was pretty straight forward. 802641



- RM-766
by:

The tow bar wiring kit fits well on my Jeep Wrangler and was easy to install. Always great dealing with etrailer, their customer service is excellent. They give great suggestions and guidance on the right products for your needs. They are a fantastic resource...saving you both time and money. 796689



- RM-766
by:

Great product.. a must if you flat tow a vehicle like my GMC Sierra truck that requires you to disconnect the battery when you tow it. Push a button and the battery is disconnected, push it again and its reconnected.. it's that simple to disconnect the battery. 790598



- RM-766
by:

good 785874



- 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. 774211



- 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. 746500



- RM-766
by:

Easy install! Instructions were great and etrailer sales help was great 745008



- RM-766
by:

simple wiring 737834



- RM-766
by:

AMAZING PRODUCT WOULD DEFINITELY RECOMMEND AND USE AGAIN 737397


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Ask the Experts about this Roadmaster Accessories and Parts

  • How Does Supplemental Braking Kit Get Power on Vehicle that Battery Gets Disconnected
    We have just what you need. For vehicles that have to have the battery disconnected to be flat towed but then use a supplemental braking system designed to draw power from the towed vehicle you'd want the outlet kit part # RM-9332. This actually wires directly to the vehicle battery so when the vehicle is disconnected it still gets power.
    view full answer...
  • Can the Automatic Battery Disconnect Be Used On a 2019 GMC Canyon Diesel
    I do have an option for you but the Roadmaster Automatic Battery Disconnect part # RM-766 will not work on any vehicle with a diesel engine no matter the number of batteries due to power surges. Instead, you can use the Deka Lead Quick-Disconnect Battery Terminal part # DW05312 or you can use the Epicord Battery Disconnect Switch with Key part # 277-000096 and mount it inside the vehicle. I have attached some other items you will need to flat-tow a 2019 GMC Canyon below. Roadmaster...
    view full answer...
  • Parts Needed to Flat Tow a 2017 Ford Edge with Push-Button Start Behind a Motorhome
    The battery does have to be disconnected to flat tow your 2017 Ford Edge with push-button start. The automatic battery disconnect, # RM-766, is recommended to do this automatically so you won't have to spend time doing it manually. This disconnect has been used on the positive terminal with other vehicles and I see no reason why you couldn't do the same on your Edge. If you need all of the other parts to flat tow your Edge then I recommend the following parts: Base plates: # RM-524454-5...
    view full answer...
  • Should Automatic Battery Disconnect and Battery Charge Line Kit be Used to Flat Tow a 2017 Ford Edge
    Yes, to keep the battery from draining by using the Automatic Battery Disconnect # RM-766 while flat towing your 2017 Ford Edge, it is recommended to use the Battery Charge Line Kit # RM-156-25. This is especially true if you have a supplemental braking system that requires 12V power to operate. Installation videos of each of these kits on a 2017 Edge have been linked to this page for you to reference. If you don't already have a wiring kit installed on your Ford Edge then I highly recommend...
    view full answer...
  • Will Battery Disconnect Unlock Steering Wheel When Flat Towing 2020 Chevy Silverado 1500
    According to the owner's manual of your 2020 Chevy Silverado 1500, Step 11 of the instructions to dinghy tow, it says: "If the vehicle has an ignition key, keep it in the towed vehicle in ACC/ACCESSORY to prevent the steering column from locking. If the vehicle is equipped with Keyless Access, keep the RKE transmitter outside of the vehicle and manually lock the doors. Access the vehicle by using the key in the door lock." I also recommend checking out the owners manual and referring to...
    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...
  • Battery Disconnect Needed When Flat Towing a 2017 GMC Sierra 1500
    The battery disconnect that you should use when flat towing your 2017 GMC Sierra 1500 is the Roadmaster # RM-766. If you don't already have a wiring kit installed on your pickup then I also recommend installing the Flexo-Coil Wiring Kit # RM-15267 and the connecting the charge line kit # RM-156-25 from the center pin of the 6-Way connector to your battery so that your battery won't drain while flat towing. I have attached some sample installation videos for you to reference. For...
    view full answer...
  • 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.
    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...
  • 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....
    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...
    view full answer...
  • Recommended Battery Disconnect System for Flat Towing GMC Canyon Diesel
    You are right that the Roadmaster Automatic Battery Disconnect # RM-766 cannot be used with diesel engine vehicles like your GMC Canyon. The issue is the high compression ratio of diesels that cause the engine to surge up to 10 times that of gas engines, which can lead to failure on the solenoid. What you can use instead is an alternate-style battery disconnect like the Deka # DW05312 or the Epicord # 277-000096 that includes a switch you could mount inside the cab. This still allows...
    view full answer...
  • Stay-In-Play DUO Braking System Installation in Vehicle That Requires Battery Disconnection
    In a vehicle like your 2018 Ford Edge that directs you to disconnect the battery when flat towing the car, the SMI Stay-In-Play Duo # SM99251 monitor light will install with its RED wire attached to the blue wire that goes between the breakaway switch and the operating unit. This step is covered in the linked instructions on page 7.
    view full answer...
  • 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.
    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...
  • How To Install The SMI Stay-IN-Play DUO Supplemental Braking System On A 2017 Chevy Colorado
    The owners manual states that you must remove the negative battery cable in order to flat tow the vehicle however, according to Roadmaster and multiple installations we have performed, you will only need to remove the positive terminal as the negative terminal will still need to be attached in order for proper functionality. To do this you will need the Roadmaster Automatic Battery Disconnect with Switch for Towed Vehicle w/ Supplemental Braking System part # RM-766 as this will allow you...
    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.
    view full answer...
  • Recommendation for Disconnecting the Battery or Running a Hot Wire When Wiring a Jeep Toad Vehicle
    You could route the power wire from the RV 7-Way trailer connector to the Jeep battery to help maintain the Jeep battery when towing. The problem is that the 12 volt circuit will most likely not be able to keep up with the amperage draw on the Jeep battery when towing, because of the distance from the RV charging system, and you would need trailer connectors to accommodate the extra wire on the tow bar jumper harness and the Jeep. I recommend installing an Auto Battery Disconnect, #...
    view full answer...
  • Availability of Battery Disconnect Switch for Flat Towing 2016 Ford Focus
    Disconnecting the negative battery cable in your 2016 Ford Focus, either manually or via a switch, will still allow the battery to provide power to a braking system like the SMI Stay-IN-Play DUO # SM99251 referenced in your question. This is because disconnecting the negative cable will disconnect the battery from the vehicle, but will not prevent it from providing power to other components. If you are interested in installing a battery disconnect switch in your Ford Focus, you can...
    view full answer...
  • Battery Disconnect for Flat Towing 2016 Ford Focus
    The battery terminal on your 2016 Ford Focus does need to be disconnected, but you are absolutely right that you can use the battery disconnect. The right one for your 2016 Focus is the Roadmaster Automatic Battery Disconnect with Switch # RM-766. I have added a link to the instructions as well as a link to a video of the disconnect being installed on a Focus for you to check out.
    view full answer...
  • Battery Disconnect Options for Flat Towed 2014 Chevrolet Spark
    In your case the better option is the Roadmaster Automatic Battery Disconnect for Towed Vehicles # RM-766 since you do not have to pull fuses in your Spark. In that other case the TowDaddy # TD704 would be the better option. The Roadmaster ABD # RM-766 eliminates the hassle of pulling your battery cable. To deliver a trickle charge to the battery via the tail light wire (when the RV lights are on) you can use # RM-156-25.
    view full answer...
  • Does the Battery on a 2018 Chevrolet Silverado 2500 Need to be Disconnected While in Tow
    Yes, the batteries on your 2018 Chevrolet Silverado 2500 must be disconnected while in tow. However, the Roadmaster Automatic Battery Disconnect with Switch part # RM-766 cannot be used on vehicles with a diesel engine therefore you would need a manual battery disconnect like the Deka Lead Quick-Disconnect Battery Terminal part # DW05312. I have attached a sample install video for you as well.
    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...
    view full answer...
  • Why Does Battery of 2018 Ford Focus Have to Disconnect to Flat Tow It
    In order to unlock the steering wheel of your 2018 Ford Focus the key needs to be in the on position. The problem with this is that it will drain the battery if left like that. So you have to disconnect the battery so that it doesn't drain and the steering wheel remains unlocked. The Roadmaster Automatic Battery Disconnect # RM-766 that you referenced is a great solution for this as it automatically disconnects the battery and with the charge line kit part # RM-156-25 it can also put...
    view full answer...
  • Can the Roadmaster Battery Disconnect # RM-766 be Used on a 2017 Ford Edge for Flat Towing
    I spoke with my contact at Roadmaster who said that the Automatic Battery Disconnect # RM-766 has to be installed on the positive battery terminal. The reason given in the owner's manual for your 2017 Ford Edge is that "You need the door key to lock and unlock doors when the battery cable is disconnected" (see page 238). Whether you disconnect the positive or negative battery cable the result will be the same; you will have to use a key because the key FOB won't work with the battery...
    view full answer...
  • Does Battery Have to be Disconnected to Flat Tow a 2015 Ford Edge Behind a Motor Home
    The negative battery cable does need to be disconnected to flat tow your 2015 Ford Edge and it is because otherwise it would drain the battery. There is a way to provide a maintenance charge to the battery but it will not charge up the battery and the battery could still drain. You can also add a battery disconnect, # RM-766, to make it easier. Roadmaster has a charge line kit, # RM-156-25, that will work with your Edge. It'll help maintain charge but, like I mentioned, won't actually...
    view full answer...
  • Does Roadmaster Battery Disconnect Work with Diesel 2020 Chevy Silverado 1500 3.0 Liter
    I checked with Roadmaster and the RM-766 cannot be used with the diesel engines likes what you have in your Silverado. The lighting kit part # RM-152-98146-7 will fit and work great in your 2020 Chevy Silverado 1500.
    view full answer...
  • Why Must the Negative Battery Cable Be Disconnected on a Jeep Wrangler to Flat Tow
    Jeep recommends disconnecting the negative battery cable when flat towing 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. For your situation, I recommend installing the Roadmaster Automatic Battery Disconnect, # RM-766, on the positive battery cable so you don't lose your ground to the chassis. I know the owners manual says negative cable,...
    view full answer...
  • Why Can't the Roadmaster Automatic Battery Disconnect be Used on a Diesel Engine
    I spoke to my contact at Roadmaster and they informed me that Roadmaster Automatic Battery Disconnect with Switch part # RM-766 cannot be used on vehicles with a diesel engine because these vehicles require a battery with a very high cold cranking amp (CCA) rating which would fry the solenoid on the battery disconnect. Instead, you will want to use something like the Deka Lead Quick-Disconnect Battery Terminal part # DW05312 which allows you to disconnect the battery leads though the use...
    view full answer...
  • Recommended Battery Disconnect Switch for 2017 Ford Edge
    On your 2017 Ford Edge, the battery must be disconnected when flat towing because Ford wants to prevent the battery from draining. When you flat tow, your vehicle must have the ignition in the ACC position, and this will leave certain electronic components on that can drain the battery. A dead battery could cause functions of your vehicle to not operate correctly when towing, so it is wise to follow the manufacturer requirements to prevent draining your battery. To make this disconnection...
    view full answer...

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Info for this part was:

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