Is the blower still not working or have you no just heat output? If the latter its probably a faulty water control valve.

Have you checked the fuse that protects the blower motor ?

Also check if the current is getting to the blower motor. If not then something further up the line is amiss.

What is the age of this fiesta?

With ignition switched on,there should be voltage present at one of the wires at the blower motor ,irrespective where the blower switch is set as the system works on an earth circuit switch.Fuse supply should be F 49 30amp in cabin fusebox.hth