I have a 2002 Focus ZX5. A few days ago I turned on the a/c and after I turned it up to high, something went wrong with it and now high is the only fan setting that works. Cold air can be felt coming out of the vent in speeds 1-3 (even though the blower isn't working), and when the fan setting is on 4 the light on the a/c button goes off, and the fan blows out the cold air that is in there and then goes back to blowing vent air through the cabin. Is there a resistor or inline fuse that has been blown? And is it an easy fix or should I take it to the dealership?

Sounds like the blower resistor went out on you. I would start there.

Thanks Mulletman!!

Is the blower resistor located near the blower or in line?

It IS the blower resistor. The same thing happened on my 2002 focus. The resistor is behind the glove box. Less than $20 from Ford dealer and 20 minutes to replace. Drop the glove box all the way down. Use a 1/4 drive 8mm with a long extension to remove the 1 screw holding the resistor in. Unplug resistor, plug new one in and replace screw. Done.

^ yup! glennzo nailed it for you!

Thanks Guys! U nailed it!