heat and ac question on 1993 Toyota Corolla

my cooling fan only works with ac and not the heat why

Asked by for the 1993 Toyota Corolla
The condenser fan operates when the A/C compressor is engaged, as part of the A/C operation. No need for A/C when the heater's on.
You also have a radiator fan, it cycles on and off to cool the engine.
The condenser fan is on the passenger's side and the cooling fan is on the driver's side.