My heater blower fan seems to have bit the dust. However, every once in a while it magically comes on. What should I check other than the switch before I start major surgery ? I sure don't want to try to pull it before I check all the other possibilities. Any tricks of the trade ? Last thing in the world I want to do is to put in a new blower fan. I'd rather change the clutch out or even sell the car before trying to replace the blower fan.