We had this problem a few times and been unable to replicate predictably for the mechanic.

Basically without warning the fan will blow hot air at full force, either at start up or when driving randomly. It doesn't change temp or speed if fan is 0-5 or even if the A/C button is pressed, or if you try to change it.

Occasionally I can get it to stop blowing by banging on the left side of the console. The radio will also very randomly screech static and the drivers side window sometimes gets stuck in the down position. Don't know if that's related though.

Any thoughts?