I've seen some chatter that Ram Truck's integrated brake controller, at low speeds (below 30?) doesn't apply full brake voltage? I wonder if the Ford is programmed like this as well?
If that's the case, you'll never achieve lockup as we are accustomed to testing it. In many brake controller instructions, it says to travel on smooth, dry pavement at 20 mph, and apply the manual brake controller fully. Increase gain until trailer tire lockup is achieved, and then back off slightly. If the controller is designed/programmed to decrease braking output at low speeds, you'll never be able to achieve lockup with that method. OTOH, if you pull the emergency plug, you're getting unbridled 100% voltage immediately.
It kind of makes sense if you think about it. An example can be found on 18-wheelers. If a tractor is towing an unladen trailer, you see the trailer tires lock up all the time at low speeds. Perhaps the integrated brake controller's programming is trying to avoid this? It could sure wear out tires fast if they were locking up at every stop.
Not saying it's a good idea, but I can see the logic in programming it this way...
Of course, I'm by no means an expert, but I did stay at a Holiday Inn Express last night! LOL!!
2014 Jay Flight 28 BHBE
2015 RAM 2500 6.4L HEMI, Tradesman 4x4, 3.73
Blue Ox SwayPro (BXW 1503)
Upgraded from an REI internal frame backpack and a Eureka 1/2 dome tent!