Depending on the make and model of your car, the aircon control unit or the thermostat may be faulty.
TO COOL IT DOWN
The fan turns on when you turn your car off so that the engine will cool down faster. It should only run for a few minutes, 10 max. But your fan also runs when your car is on not just when it is turned off.
Maybe the fan cooling your car off.
it is still running off the battery, most of the time it will turn off when you open the door
It's probably the catalytic converter fan; not the a/c fan.
Check and change the relay
fuse, wiring.... how long do u let it run before turning it off??..I would look to the fan relay next. also the electric fan thermostat if the car has one
turn the engine off try turning the fan if it doesnt turn the clutch on the fan is bad it
The fan motor is controlled by a thermostat. When you turn off your car if the water temperature is higher then the thermostat is set for. the fan will continue to run until the temperature comes down then shut off. If the thermostat is faulty the fan will either run continually or not at all.
With many cars now days, the fan may continue to run after the car is shut off, or they may even start and run for a while after the car is shut off. An engine will actually get hotter for a short time after being shut off. Sometimes that will trigger a sensor to turn on the cooling fan. If it continually runs after being shut off, it could be a faulty temperature sensor, or a faulty fan relay, or even a bad computer.
It sounds like the fan-belt is slipping.
Most likely cause is that the rev limiter has cut in.