the easiest solution is to get a garage to check out the problem,i know dealers are expnsive but it shouldnt take no more than 1 hour to diagnose the problem then when they do so fit the part yourself,its pretty handy to work on that model.at a guess and ive done a few id say the motor may be at fault but again a simple test of the heater electrical circut will show were the fault lies
hope this helps
r500c, January 2009
