I'd used the house air conditioning few days recently and set
thermostat high not to run it.
Last night, I found that the outside air conditioning cooling fan had
kept running over hours even if I set the air conditoning off and set
fan off from the thermostat. I heard a minor sissing air noise at the
air conditoning unit, not the cooling fan. It seemed the air
conditoning unit was doing something.

I was afraid of burning the cooling fan moter off and turned off its
power from the central power box in the basement. Now the cooling fan
is stopped running. It's 2 years old house, and this is the first time
it happened.

Could you adive me what to do with it?