Why Must the Negative Battery Cable Be Disconnected on a Jeep Wrangler to Flat Tow
Question:
I was reading the manual on my 2014 Jeep Wrangler Sahara and it says Disconnect the negative battery cable, and secure it away from the negative battery post. Why is this? I will be using a portable brake controller like the Patriot so I need power for the portable brake controller. What is your advise on setting the Jeep up to charge the battery while towing and providing a quick disconnect to the battery to comply with the manual. Thanks for your help and advise.
asked by: Mike W
Helpful Expert Reply:
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, but this is the tested and recommended method from Roadmaster. To run a battery charge line to your Jeep's battery, I recommend using the Battery Charge Line Kit, # RM-156-25.
A more economical option would be the Battery Terminal Quick-Disconnect, # DW05312. This is permanently installed on the battery cable and terminal and allows you to easily disconnect the battery cable each time you want to tow. You can still use the Battery Charge Line Kit with this disconnect.
To provide power to your supplemental braking system, I recommend using the 12 Volt Outlet Kit, # RM-9332. This kit attaches directly to the battery terminals and provides an accessory outlet to power your braking system.
I have attached a few demonstration videos for you to check out.
Products Referenced in This Question
Deka Lead Quick-Disconnect Battery Terminal - Universal Polarity
- Wiring
- Wire Connectors
- Quick Disconnects
- Deka
more information >
Roadmaster Battery Charge Line Kit for Towed Vehicles
- Accessories and Parts
- Tow Bar Wiring
- Battery Charge Line Kit
- Roadmaster
more information >
Product Page this Question was Asked From
Roadmaster Battery Disconnect with Switch for Towed Vehicle w/ Flat Tow Brake System - Gas
- Accessories and Parts
- Tow Bar Wiring
- Auto Battery Disconnect
- Roadmaster
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Vehicle Tow Bar Brake System
- Shop: Base Plate for Tow Bar
- Shop: Vehicle Tow Bar Wiring
- Shop: Demco Stay-IN-Play Duo Flat Tow Brake System for RVs w/ Hydraulic Brakes - Proportional
- Shop: Roadmaster Battery Disconnect with Switch for Towed Vehicle w/ Flat Tow Brake System - Gas
- Shop: Roadmaster Battery Charge Line Kit for Towed Vehicles
- Shop: Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit
- Shop: Blue Ox Acclaim Non-Binding Tow Bar - Coupler Style for 2" Ball - Car Mount - 5,000 lbs
- Shop: Blue Ox Base Plate Kit - Removable Arms
- Search Results: bx1134
- Shop: RoadMaster Stop Light Switch Kit
- Search Results: sm99251
- Search Results: rm~156~25
- Shop: Fifth Wheel Hitch
- Video: Blue Ox Base Plate Kit Installation - 2013 Jeep Wrangler Unlimited
- Search Results: 92~00~0600
- Search Results: rm~766
- Search Results: rm~751452
- Video: Roadmaster Battery Charge Line Kit Installation - 2015 Jeep Wrangler
- Video: SMI Stay-IN-Play DUO Braking System Installation - 2019 Jeep Wrangler
- Video: Roadmaster Automatic Battery Disconnect Installation - 2014 Jeep Wrangler
- Video: Roadmaster Diode 7 to 6 Wire Coil Kit Installation - 2014 Jeep Wrangler
- Video: SMI Stay-IN-Play DUO Braking System Installation - 2013 Jeep Wrangler
- Video: RoadMaster Stop Light Switch Kit Installation - 2014 Jeep Wrangler
- Q&A: Does SMI DUO Stay N Play Create Vacuum for Vacuum Assist Brakes
- Search Results: y02~480b
- Shop: Roof Rack
- Shop: RV Camera
- Shop: Trailer Hitch
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)