One of these:
This seems to be the recommended fix if the blower stays on all the time BUT I just want to report that in my case the fan stayed OFF in my case. I knew the motor was good because I removed it and connected it to a 12V battery and WHOOOOOOSSHHH!!!! Off it went!
The consensus (as far as I can tell) for the "motor is OFF" scenario is that it is likely to be the ignition switch - happily not in my case
The thought of attacking dash wiring looms and ignition switches fills me with dread so I just gambled and went straight for the resistor and despite it being Friday the 13th my gamble paid off! Lightning despatch too - only ordered it yesterday!
Might have been a waste of money but I figured it's still a fast and cheap way to confirm the ignition switch was my next port of call rather than book it in to Auto Electrix for them to have a look maybe next week if I'm lucky. BUT! As it turns out it WAS a bust resistor unit
Easy to fit despite being under the dash in the passenger foot well - two 6mm screws and bosh out she comes!