I was googling "focus fan problem" and found your post. I am having the EXACT same problem down the fan only working in the four position. I was wondering if you were able to solve the problem?
I have a 2000 Ford Focus. A while back, my blower motor stopped working. Rather than just replacing the blower, I attempted to fix it by replacing the brushes in the blower motor. At first it worked great. Then I noticed that the blower stopped working when the switch was turned to the 1 position. Then it stopped working in positions 1 and 2. now, the A/C only works when the blower switch is at 1, 2, or 3, and the blower only works when the switch is turned to 4. So the only way I get cool air is when I go down the road at 70 mph with the window cracked open a bit and the switch turned to 1, 2, or 3. I replaced the blower switch thinking this might be the problem, but it still does the same thing. I noticed that when I took the A/C console apart, to replace the blower switch, all of the bulbs inside were burned out. I have traced the wires from the switches and can't find any shorts, breaks or burns. I didnít hook them to any meter though, so I canít be certain that a short doesnít exist. I was told that probably the blower motor fan speed resistors had blown, and I should replace them.
Anyone else had similar issues?