HI, I HAVE THE SAME PROBLEM, I DID CHANGE THE SWITCH BUT NO LUCK WITH THE POWER OR FAN.HOPE SOME 1 OUT THERE CAN GIVE US AN ANSWER AT THIS TIME OF THE WEATHER!! MERY XMAS.
Just checked the heater on my daughter's car as it wasn't blowing at all. I found the connector block on the heater unit (passenger footwell) had been disconnected....probably her big-footed husband. Just connected it again and all ok
Bob, December 2010
Does your temperature gauge go balistic as well ?.
GLYN, January 2009
First thoughts - check the fuse in the fuse box is it OK? Check the wires connecting the fan unit (under the glove box) - are they loose?