I have owned a 2004 Crossfire for about a year now. Lately, it seems like the blower fan has a mind of it's own. When I start the car, the fan will be running in what I would consider a normal speed. It will suddenly speed up, sometimes for a few seconds, sometimes for several minutes, and the slow back down to the original speed. It doesn't seem to matter if the a/c is on or off, nor does it seem to be temperature dependent. When the fan speeds up, moving the fan speed switch still increases or decreases the speed, but it continues to run even on the '0' position. I'm not sure if this is as designed, or if there's some type of issue.

 

pounded on my dash board, just above where the fan sets, and next thing you know it fixes it's self... go figure... hooah... take it into the dealership, there is a problem with the fan, it should not run fast and slow unless you turn the fan motor switch up and down in speed range... next thing you know the you can change the name from Crossfire to just "FIRE".

 

I have the exact problem, it seems to happen only with the heat on.
I can live with it.
Good luck.