I have an 8yr old Carrier HP we changed to heat several nights ago. Today I noticed the fan wasn't running. The unit clicks back and forth ( 2 distinctly different clicks). The motor gets hot but the fan doesn't run. Fan spins freely. Tried switching back to AC and it does the same thing, clicks but doesn't run. A few weeks ago it ran fine on AC. Any ideas? We live near Augusta Ga and the unit has worked fine until now.