How Does Supplemental Braking and Lighting Work on a Flat Towed Vehicle with Ground Disconnected

Updated 03/22/2017 | Published 03/21/2017

Products Featured in This Question

Blue Ox Patriot Portable Flat Tow Brake System - Proportional

(456)

$1404.09

12 Volt Outlet Kit, 20 amps

(358)

$37.12

Question:

FORD SAYS TO DISCONNECT THE GROUND CABLE AT THE BATTERY..HOW DOES THE TAIL LIGHTS AND THE BRAKE BOX WORK WITH NO GROUND

asked by: DAVID S

Expert Reply:

It's actually pretty common for the manufacturer of a vehicle to recommend disconnecting the ground of the battery of the vehicle while it's being flat towed. To power the supplemental braking system like the Blue Ox Patriot part # BLU37TR you would need to use an outlet kit like part # RM-9332 which wires directly to the battery.

The taillights of the vehicle will be powered and grounded by the tow vehicle actually. Since the power and signal comes from the vehicle that's doing the towing the battery of the towed vehicle being unplugged is not an issue. Also the grounds for the taillights will go through the body of the vehicle, to the frame of the vehicle, to the base plates, to the tow bar and then back to the tow vehicle.

expert reply by: Jameson C