Hi, could be something jamming/blocking the fan blades and the air vent at same time you'll need to take the lower air ducts off the main body of the heater/blower to look inside. Other thing it could simply be the elec. fan motor's giving up & you'll need a new one.
Chris P.Duck
February 2010
oh by the way its a 2002 Rover 45 ;-)
debbie
February 2010
Automatic Answer
We may have found other answers which could help you.