When I turn on fan(same condition regardless of a/c or heat, etc.) it sometimes works, sometimes not. Do not see any fuses blown. If left turned on it will eventualy kick on, once on it works fine until shut off. Guessing could be issue with the dash switch or other electrical item?
A/C and heat both, no air blowing when turned on sometimes on 2004 Chevrolet Impala
Sounds like you have a bad winding in the blower motor, next time it gives you grief, to prove the issue leave the heat on, and tap on the blower motor a few times. It should start running. If this is the case, the blower motor needs replaced.