Re: Heater fan problem - please help!
I've taken a look at the wiring diagram for a 99 model (same as mine) and I can't see how this can happen. The fan motor is connected solidly to earth (negative), and it is the live (positive) that is switched. The live can only reach the fan motor via the resitor pack, which in turn gets its positive connection from the fan speed switch on the dashboard. So even if the live were still connected to the speed switch, you should still be able to turn the knob to switch off the fan. The live to the speed switch comes from relay J35, which is energized by the ignition switch. You would have to have a duff relay (J35) and a duff fan speed switch (H81) as well.
You're not the only one who's had this problem though. I found another posting that appeared to be about the same problem, but it received no replies.