How to Use Supplemental Braking on a Vehicle Where Battery is Disconnected

Published 03/19/2015

Question:

I dont understand why a battery disconnect is needed while flat towing my 2011 wrangler. I will be using a tail/brake light wiring harness and a blue ox patriot with a brake light relay. Can I simply add a charging wire with diode from the rv to maintain the jeep battery?

asked by: Rick

Helpful Expert Reply:

From what I have found in my research, to flat tow the vehicle the ignition key must be turned to the first or accessory position. This is so the steering wheel unlocks. Even with all accessories in the vehicle switched off, this creates sufficient draw on the battery to discharge the battery gradually while towing. After around 5 hours, the battery will not have enough charge to start the vehicle.

I recommend using the Roadmaster 12 Volt Outlet Kit, part # RM-9332. This attaches to your battery and will provide the power needed for a portable supplemental braking system.

I attached a couple help articles for you to check out as well.

expert reply by: Jameson C