If you think it might be a switch issue remove the plasic panel under the dash their short small stubby screws once removed you will see a large number of wires about an inch thick cable tied either side of the air con rotating knob, cut both cable ties and move the loom to one side and you can gain access to the two switches. I did this to mine and also found out why the heated screen stopped working. It was a water ingress problem from the windscreen washer pipe. That's another story flippin nightmare......
