has it got the climate pack ? i cant remember (or be bothered to look) if the st200 has climate control as standard

if so its probably the controller for the climate control

if not the blowers on full is probably the resistor pack and wires melted , this is a common fault on mondys and ford released a revised version of the pack and wires , they are situated in the passenger footwell behind the glovebox to the right , easy job to change when you find it !