Ford has provided the wiring for a trailer electric brake controller on the F-53 chassis since at least the early 2000s.
The front-end wiring is there, but prior to 2012 it could be a bear to extract the connector from the wiring inside/under the dash. In 2012, Ford moved the front connector plug so it would be easier to find. It is clipped to the left side of the steering column, immediately to the right of the parking brake release handle. It is a gray, 6-pin rectangular connector, with red, white, blue, green and brown wires.
Please don't cut off the Ford-provided connector to wire in a controller. Instead, buy this pigtail adapter
and, if you don't have a Tekonsha controller, cut the Tekonsha connector off the pigtail adapter and butt-splice that
to the brake controller. By so doing, you leave the Ford wiring intact for the next owner.
The Ford wiring ends in two connectors at the rear of the frame, usually inside the left frame rail. The Ford brake controller wire at that point is blue. The "coach builder" (Thor, in this case) has the option of extending that wire to the trailer hitch connector. The color of that extension, if any, is up to the coach builder.
I should hope that in 2017 ALL manufacturers extended the Ford-provided electric brake controller wire, but cannot say for certain in any specific case.
Information on the 2017 F-53 chassis is here
, linked to from the Ford Body Builders Layout Book, here