That code on a Ford is typically a wiring problem or bad ABS module. Check the wheel sensors like you said, but also the wiring.

C1185 is a power relay circuit problem, if the Internet is correct. (They can't put anything on it that isn't true, after all.) This is internal to the module, or a power or ground is missing. I have a vague recollection of a large ground wire or wires causing problems on a similar truck. It was on top of the frame, inside the right front wheel well.