Found out yesterday that I seem to be having similar issues with my 2006 STI. I got in my car yesterday and started it up and I usually keep my fan on all the time and noticed that my defroster wasn't working. I turned the switch off and on again and nothing. I tried pressing the recirc button and also the AS button a few times and kept trying to turn it on and off. When I turn the fan dial on and off I can hear a relay clicking under the dash on the driver side. After I messed with it for a bit by turning it on and off it started working. The next time I got in my car and started it up it was the same thing but the time after that when I started the car it started working right away so it seems to be an intermittent issue. Anyone have any ideas on what it could be. I was reading some of the posts and it looks like it could be an issue with the resister/transistor but I'm not sure of if it is the same with an 06?... I'm assuming it would be pretty close if not the same. Any ideas on what to check?