You don't say what year your F53 is and that is an important factor. On my 2000 F53 the VSS (Vehicle Speed Sensor) was bad. It is mounted on top of the "pumpkin" with one screw and it provides data for the ABS and speedometer I think as well as probably other systems. It caused the ABS light to come on sporadically but the speedo worked fine. I agree it is generally best to "get it scanned before just changing parts" but a cheap OBDII code reader will not read the ABS codes. You will need something or a mechanic that can read Ford specific trouble codes. Sometimes it may be cheaper to replace a cheap part or two instead of paying for a mechanic to troubleshoot the problem. My VSS only cost about $20 in stock at NAPA. The problem could be wheel sensors, a bad connector, damaged wires, brake control unit and on and on. I would suggest you visually inspect all the wires and connectors you can, clean the wheel sensors (they collect metal particles) and check the sensors with an OHM meter. That covers a lot of the simple stuff with not too much effort when the snow melts. My failed VSS measured as an open circuit. That was a good clue.
