FORD 2013 Flex v.4 - Manual (Page 266)

Trailer Brakes
WARNING: Do not connect a trailer’s hydraulic brake system
directly to your vehicle’s brake system. Your vehicle may not have
enough braking power and your chances of having a collision greatly
increase.
Electric brakes and manual, automatic or surge-type trailer brakes are
safe if you install them properly and adjust them to the manufacturer’s
specifications. The trailer brakes must meet local and federal regulations.
The rating for the tow vehicle’s braking system operation is at
the gross vehicle weight rating, not the gross combined weight
rating.
Separate functioning brake systems are required for safe control
of towed vehicles and trailers weighing more than 1500 pounds
(680 kilograms) when loaded.
Trailer Brake Controller Connector (If Equipped)
The connector is located under the
instrument panel above the brake
pedal.
Towing 265
2013 Flex (471)
Owners Guide gf, 4th Printing, December 2012
USA (fus)