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Roadmaster Battery Ace Battery Disconnect w/ Key Fobs - Gas Only
Roadmaster

Roadmaster Battery Ace Battery Disconnect w/ Key Fobs - Gas Only

Part Number: RM39ZT
In Stock
$149.39
Retail:$225.08
You Save: $75.69
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If you need to disconnect the battery to flat tow your vehicle, you're going to want this kit. It disconnects your battery with a compact key fob - much safer and faster than doing it yourself - while keeping your towing accessories charged. 1-800-940-8924 to order Roadmaster accessories and parts part number RM39ZT or order online at etrailer.com. Free expert support on all Roadmaster products. Great prices and Fastest Shipping for Roadmaster Battery Ace Battery Disconnect w/ Key Fobs - Gas Only. Accessories and Parts reviews from real customers.
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  • Reviews (4)
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Roadmaster Accessories and Parts - RM39ZT

  • Flat Tow Wiring Harness
  • Battery Disconnect
  • Roadmaster

If you need to disconnect the battery to flat tow your vehicle, you're going to want this kit. It disconnects your battery with a compact key fob - much safer and faster than doing it yourself - while keeping your towing accessories charged.


Features:

  • Disconnects your battery with the push of a button with a compact key fob
  • No stringing wires through the firewall or mounting switches to the dash
  • Includes Faraday pouch to block RF signals and prevent accidental activation
  • Eliminates the inconvenience and danger of pulling your battery cable yourself
  • Provides a positive current source for the breakaway switch and other accessories without draining the battery
  • Includes a corrosion-resistant, marine-grade solenoid with 200-amp constant duty and 600-amp surge
    • Comes pre-assembled for easy installation


Specs:

  • Application: vehicles that require the battery to be disconnected for flat towing - consult your owner's manual
    • Works with almost any 12V or 24V battery
    • For gas engines smaller than 8 cylinders only


Notes:

  • 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.
  • Disconnecting the battery, whether manually or with this automatic disconnect, will affect your vehicle's electronics. You will need to reset various electrical components in your vehicle following use of this product.
  • A charge line kit (RM-156-25 - sold separately) is recommended if you have a braking system that is using power from the towed vehicle's battery while it is disconnected.


768 Road Master Battery Ace Automatic Battery Disconnect Switch for Gasoline Vehicles with Key Fobs





Customer Satisfaction Score:

Ratings & Reviews

3.5

4 reviews
Review sort icon
If you need to disconnect the battery to flat tow your vehicle, you're going to want this kit. It disconnects your battery with a compact key fob - much safer and faster than doing it yourself - while keeping your towing accessories charged.

by:



by:



by:

Very easy install and works as advertis ed.



by:

Never worked correctly from the start. Disconnect would disconnect the battery randomly and finally it wouldn't reconnect battery after a couple weeks. Warranty process was just too much leg work and time to make it worth it. Puled it out and tossed it in the trash. Put in a manual positive on/off disconnect switch. I was weary of the remote deal to begin with and my concerns were unfortunately valid.


4
4

See what our Experts say about this Roadmaster Accessories and Parts

  • Recommended Parts for Flat Towing a 2023 Lincoln Nautilus
    Hey Randy. Blue Ox and Roadmaster's tow bars and baseplates are pretty comparable but Roadmaster's wiring options are far superior. Please note that the you can only flat tow your Nautilus if it has the 2.7L V6 engine. To flat tow your 2023 Lincoln Nautilus I recommend the following parts from both Roadmaster and Blue Ox: Tow Bar and Safety Cables - Blue Ox Avail Non-Binding Tow Bar item # BLU28QV and item # BX88197 Base Plate Kit - Blue Ox Base Plate Kit item # BX2680 Wiring Harness...
    view full answer...
  • Recommended Battery Disconnect for a Flat Towed 2025 Chevy Trailblazer
    Hello Floyd, Thanks for writing in. Since your 2025 Chevy Trailblazer requires a battery disconnect while flat towing, I recommend the Roadmaster Battery Ace Battery Disconnect with Key Fobs # RM39ZT. What I like about this system is that it takes the guesswork out of the battery disconnect procedure. Once installed, it provides a consistent way to disconnect the battery for towing and reconnect it when you're ready to drive. That helps eliminate the possibility of forgetting a step...
    view full answer...
  • Braking and Electrical Parts Needed to Flat Tow a 2021 Chevrolet Colorado Gas or Diesel
    Hey, Glen! The best brake system for your 2021 Chevrolet Colorado is going to be the Demco Stay-IN-Play Duo Braking System part # DM86VR. Once installed it will make flat towing easy especially with the wireless monitor you will have with you in the front of the RV. I did go ahead and check into all the other electrical parts you will need to flat tow. If you have a gas model you will need the Roadmaster Battery Ace battery disconnect part # RM39ZT. However, if you have a diesel model...
    view full answer...
  • What Roadmaster Parts do I Need to Flat Tow My 2014 Jeep Wrangler Sport Behind RV?
    Hello Thad, Happy to get you the parts needed to flat tow your 2014 Jeep Wrangler behind your RV so you can be on the road to adventure! Here is the complete package you will need (I am including the parts you already have): - Base Plate: Roadmaster Direct-Connect Base Plate Kit - Removable Arms # RM-521448-5 - Tow Bar: Roadmaster Nighthawk All-Terrain Tow Bar w/ LED Lights - Non-Binding - RV Mount - 8,000 lbs # RM-676 - Wiring: Roadmaster Universal Hy-Power Diode Wiring Kit # RM-152...
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  • Complete Flat Tow Set-Up for 2025 Chevrolet Colorado ZR1
    Hello William, Happy to get you a flat tow package put together for your 2025 Chevrolet Colorado ZR1. I have also attached our Dealer Locator so you can see who is in your area that you can trust to complete the installation. For the base plate, I recommend the Roadmaster Direct-Connect Base Plate Kit with Removable Arms # RM28GR. This gives you the attachment points needed to connect your truck to the tow bar, and the removable arms help keep the front of your Colorado looking clean...
    view full answer...
  • How To Tow A Vehilce With an etrailer Baseplate and a Roadmaster Falcon Tow Bar
    Hey, William. Thanks for your question. To use the etrailer Invisible Base Plate Kit # e24FV, you can use adapter kit # e99037 or # DM9523036. The # e99037 kit includes two different adapters, but you would only use one of them. The # DM9523036 comes with exactly what you need without any extra parts. For a braking system, the Demco Stay-IN-Play Duo # DM86VR is the route you want to go in. It’s compatible with the electric assist brakes on your 2026 Buick Encore GX. It sounds like you’re...
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  • Recommended Flat Towing Parts for a 2013 Smart Fortwo
    I'd be happy to Chris. To flat tow a 2013 Smart Fortwo, I recommend the following parts: Tow Bar and Safety Cables - etrailer SD Non-Binding Tow Bar for Blue Ox Base Plates item # e47ZR Base Plate Kit - Blue Ox Base Plate Kit - item # BX1987 Wiring Harness - Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit item # RM-15267 Battery Disconnect Switch - Roadmaster Battery Ace Battery Disconnect w/ Key Fobs item # RM39ZT Supplemental Braking System - SMI Stay-IN-Play DUO Supplemental...
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  • Recommended Parts to Flat Tow a 2019 Ford Fiesta ST-Line w/a Automatic Transmission
    Hey Martin. Here's a list of parts that are a mix of what you referenced and what I recommend using to flat tow your 2019 Ford Fiesta ST-Line: Tow Bar and Safety Cables - Roadmaster Falcon 2 Tow Bar item # RM-520 and item # RM-643 Base Plate Kit - Roadmaster Direct-Connect Base Plate Kit - item # RM-524441-5 Protective Screen - Roadmaster Tow Defender Protective Screen for Towed Vehicles item # RM-4750 Wiring Harness - Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit item # RM-15267 Battery...
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  • Recommended Flat Towing Parts for a 2022 Chevy Traverse
    Hey Randy. The 2022 Chevy Traverse can indeed be flat towed. GM issued the technical service bulletin PIT5890 that corrected the original misinformation in the owner's manual and detailed the setup process. To flat tow your 2022 Chevy Traverse, you'll the following parts: Tow Bar and Safety Chains - etrailer XHD Non-Binding Tow Bar item # e94ZR. This baseplate works with or without the Active Aero Shutters. Base Plate Kit - etrailer Invisible Base Plate Kit item # e36GV Wiring Harness...
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  • Complete Roadmaster Flat Tow Set-up for 2024 Chevrolet Tahoe Towed Behind Itasca Sunova
    Welcome to etrailer David, Congrats on the Class A Winnebago!! Have you been able to take it out on its first trip yet? You can flat tow your 2024 Chevy Tahoe as long as it is the 4 wheel drive model. You will want to double check your owner's manual to make sure you follow the correct flat towing procedure. Also, you did not mention if yours is a Z71. If it is, please let me know so I can adjust a couple of the parts if needed. Here is the setup I would recommend: Base Plate: Roadmaster...
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  • Recommended Baseplate for a 2026 Chevy Blazer w/a 2L Turbo Engine and Adaptive Cruise Control
    I sure do Steve and congrats on your new SUV! For a 2026 Chevy Blazer with the 2L turbo engine and adaptive cruise control, you'll need the Blue Ox base plate item # BLU68QV. This kit comes with the removable arms and all the hardware you'll need to complete the installation. Here are the rest of the parts you'll need to flat tow your 2026 Chevy Blazer: Tow Bar and Safety Cables - Blue Ox Avail Non-Binding Tow Bar item # BLU28QV and item # BX88197 Wiring Harness - Roadmaster Diode 7-Wire...
    view full answer...
  • Battery Disconnect for Jeep Grand Cherokee
    Thanks for letting us help Bob. We do carry a battery disconnect with a wireless remote with the Roadmaster Battery Ace Battery Disconnect # RM39ZT. This system is primarily designed for vehicles that require the battery to be disconnected while flat towing, but electrically, it can accomplish what you're looking to do by allowing you to disconnect and reconnect the vehicle battery remotely. One important limitation is that the # RM39ZT is not compatible with 8-cylinder engines. If your...
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  • Does 2019 Chevy Silverado Need a Battery Disconnect
    Hi Kenneth, Yes, you will need a battery disconnect for your 2019 Chevrolet Silverado 1500, but which one you need depends on your truck. If your Silverado is a 4- or 6-cylinder gas model, you can use a remote disconnect like Roadmaster Battery Ace Battery Disconnect w/ Key Fobs - Gas Only # RM39ZT or a push button disconnect like Roadmaster Battery Disconnect for Towed Vehicle w/ Flat Tow Brake System - Gas Only # RM-766. If your Silverado is a 8-cylinder gas or a diesel model, you...
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Info for this part was:

Employee Jeff D
Installed by:
Jeff D
Employee Joshua S
Video Edited:
Joshua S
Employee Dustin K
Video Edited:
Dustin K
Employee John S
Video Edited:
John S
Employee Wilson B
Updated by:
Wilson B
Employee Jonathan Y
Video by:
Jonathan Y
Employee Ethan H
Video by:
Ethan H
Employee Katherine B
Edited by:
Katherine B
Employee Bradley B
Test Fit:
Bradley B
Employee Jesse B
Test Fit:
Jesse B
Employee Scott A
Test Fit:
Scott A
Employee Sabrina W
Written by:
Sabrina W

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