All the fan will do is potentially effect the accuracy of the sensor, nothing to do with it not working at all.
OK, thanks. While I had it apart, it didn't look too hard to scrap all the electronics and put in an Arduino with decent range wireless. The Temp/Humidity sensor is $4, the Barometer $6, I can find out what sort of signal the wind direction thingy is providing, the rain gauge is a simple counter as is the wind speed. I am thinking $20-tops including wifi and a few hours programming.
A new wireless system would be good as I had to mount this much closer to the house than I liked as the radio range is pretty sad. The wind speed is always about 10mph low where it is, but, if I put it out in main wind stream about 150-feet away, the radio gets very spotty and unreliable.
I can put in a 916/918MGHz radio for 7-bucks with a range of half a mile. Since I know the radio protocol that acurite use, I could even use a 433MGHz and beam it to the old LCD desktop thingy. But doubt I'd waste the time when I can send it to a browser.