Stu ... Found this on-line ... !!! ... the blower motor speed resistor on a boxer van is behind the glovebox.
you have to remove the lower part of the dash on passanger side, 6 screws hold it in place, 2 in glovebox, 3 along bottom of dash and 1 by the side window vent which is on the side of dash as you opened the door.
before you pull it away unplug speaker . resistor is underneath fan motor held in by 2 screws, has wiring plug on it with 4 wires
Russ, February 2010