To be pedantic, there is no resistor in the heater control circuit to fail and cause lack of blower - it is transistor controlled and failure of that will cause full speed. There is a thermal fuse in the transistor module which can suffer from corrosion and stop the blower working, but the most common failure I've seen is the failure of the earth to pin 3 of the control PCB. Some pictures here to show you how to gain access:rutter123 wrote:Blower is prob down to blown resistor in the fan unit or the motor can seize, easy enough to check with a multimeter. sometimes the heater control panel can give probs with the tracks being dirty
http://www.bxclub.co.uk/forum/viewtopic.php?f=15&t=5515
Dirty tracks will tend to give an unstable speed, and non-linear control rather than complete failure.