Originally Posted by rancherwilli
The technician explained it as uncontrolled braking action where the trailer is receiving a 12v signal that effects the brakes but no coordination with the tow vehicle. The last owner had no controller and drove it that way for three years with his chev 1500. He further stated that uncontrolled braking can result in total brake lockup..
I think the Ford technician is giving you a line of BS. I've had 6 Ford trucks with the towing package and even the latest (a 2010) needs a brake controller (either built in or as an add on) to activate the trailer brakes. The brake lights will illuminate without a controller but no power will be transmitted to the brakes themselves.
The controller not only sends the power to the brake magnets it also controls how much and when it's sent. If you were to apply a full 12 volts to the brakes the wheels would lock up on all but the heaviest trailers. Not only would the wheels lock up they would do it at any brake pedal pressure and at any speed.
I regularly pull a 2,100 lb dual axle trailer with a load capacity of 10,000 lbs. 3 volts at the magnets is enough to stop it empty. 8 volts will stop it nicely with an 8,000 lb load. 12 volts will lock the wheels even with a full 10,000 lb load