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
- Flat Tow Wiring Harness
- Battery Charge Line Kit
- Roadmaster
more information >
Product Page this Question was Asked From
Roadmaster Battery Disconnect for Towed Vehicle w/ Flat Tow Brake System - Gas Only
- Accessories and Parts
- Flat Tow Wiring Harness
- Battery Disconnect
- Roadmaster
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Roadmaster Nighthawk All-Terrain Tow Bar w/ LED Lights - Non-Binding - RV Mount - 8,000 lbs
- Shop: Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Way to 6-Way Coiled Adapter Cord
- Shop: Roadmaster Battery Charge Line Kit for Towed Vehicles
- Video: Roadmaster Brake-Lite Relay Kit Comprehensive Review
- Shop: Demco Stay-IN-Play Duo Braking System for RVs w/ Hydraulic Brakes - Wireless Monitor - Proportional
- Article: Flat Towing Package for 2007-2018 JK Jeep Wrangler and Wrangler Unlimited
- Shop: Roadmaster Nighthawk All-Terrain Tow Bar for Blue Ox Base Plate - Non-Binding - LEDs - RV Mount - 8K
- Shop: Roadmaster Direct-Connect Base Plate Kit - Removable Arms
- Shop: etrailer SD Non-Binding Tow Bar for Roadmaster Direct-Connect Base Plates - RV Mount - 6,000 lbs
- Search Results: base plate for tow bar
- Video: An In-Depth Look at the Roadmaster Battery Charge Line Kit for Towed Vehicles
- Search Results: diode kit flat tow wiring harness
- Video: Install: Demco Stay-IN-Play Duo Braking System for RVs w/ Hydraulic Brakes on a 2012 Jeep Wrangler
- Video: Comprehensive Review: Roadmaster Brake-Lite Relay Kit for Towed Vehicles
- Video: Setting Up Your Demco Stay-IN-Play Duo Braking System - 2016 Jeep Wrangler
- Video: How to Install the Roadmaster Direct-Connect Base Plate Kit on a 2013 Jeep Wrangler
- Search Results: rm~156~25
- Video: An In-Depth Look at the Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit
- Search Results: rm15267
- Search Results: rm15267
- Search Results: dm86vr
- Search Results: demco stay~in~play
- Q&A: Will Blue Ox Base Plate Kit BX1133 Fit AEV Tubeless Bumper
- Q&A: How To Flat Tow Jeep Wrangler JK with AEV Front Bumper Using Blue Ox Base Plate Kit
- Q&A: Replacing 6-Way on Trailer With 7-Way Connector
- Q&A: Parts Needed to Flat Tow a 2013 Chevrolet Sonic Sedan Automatic Behind a Motor Home
- Q&A: Best Supplemental Braking System for Flat Towing a 2022 Ford F-150
- Q&A: Installing Brake Relay Switch On 2013 Jeep Wrangler Unlimited For Flat Towing Behind Relay
- Article: Roadmaster Vehicle Specific Base Plates
- Q&A: Should There Be Any Gap Between The Roadmaster D-Ring Adapter And The D-Ring
on Accessories and Parts
