If I recall the fan is mounted on isolation blocks like this. In the 45S head I picked up a year ago the blocks where hard and cracked. I don't think the 60km drive home in the back seat of truck did them any good either. You might look into replacing them. The switch idea is interesting another alternative would be an external fan of some sort.

http://www.vibrationmounts.com/RFQ/VM01003.htm - no knowledge of this company beyond google. Electronic parts suppliers may also be a source.