The fan may be stuck or just plain broken:
To clean it out and spin it, you must take off the cowl. To do this, take off the chrome trim in front of it. Then take off the 4 cowl screws (2 on the driver side and 2 on the passenger). The fan is in the middle all the way down. It's pointed upwards and you can see the blades. Make sure it isnt clogged or stuck.