Funny, just having a look at RAVE, cheers.There's also a resistor pack according to the electrical manual, speeds 1, 2 and 3 go through resisters to give a slower speed while speed 4 switches a relay to apply full voltage to the blower motor. I'd suspect the resister pack. Check Rave on how to remove it and check with a multimeter for a resister open circuit. New resister pack is about £20 from stealers.
which one would I need, wattage that is ?If you can determine the resistor value that is duff then a replacement resistor from Maplin is cheaper.