The engine cooling fan will continue to run because the engine is hot. Once the engine has cooled down the fan will shut off. If it never shuts off you may have a bad temp switch or relay.
The radiator fan should not run after the key is shut off. The normal cause is a failed radiator fan relay.
the Fan motor will keep running fort a short time after the car is shut off. the motor actually gets hotter after it is shut off so the fan cools it for a few minutes before cutting off. Actually, on all the mid 80s 300zx engines, there is a fuel injector cooling fan that directs cooling air on the injectors for a specific amount of time after the car has been run at normal operating temps and then shut off. Is your car a turbo z? If so then the fan that comes on is the fan that cools off the turbo after the key is shut off. Maybe you have an aftermarket fan set up for the air conditioner, but there again they usually come on while idling with the air on, but they generally shut off when the key is turned off. The fan is not used for cooling the turbocharger. The turbocharger itself is watercooled and does not have a need for a fan. The electric fan is for cooling the fuel injectors as mentioned in the previous post.
Have your blower motor resistor or blower motor checked out
The fan remains running after the vehicle shuts off in order for the engine to cool down. Once the motor cools down sensors trigger the fan to shut it off.
Fan motor? Check fuse, Check resistor pack at fan motor Check coolant level
The fan should turn off after the engine is shut off. If it stays on, the radiator fan relay has failed.
The cooling fan is operated by an electric motor rather than the revolutions of the car's motor. If your fan is staying on I would investigate the electrical systems leading to the fan, if the key is in the on position it is probably allowing power to pass to the electric motor. Otherwise there may be some short in a switch that is meant to shut it off.
Engine Temperature Sensor Doesn't Work.
The most common problem when a car's heater fan doesn't shut off when the car is shut off is that the resistor on the blower motor has gone bad. The fuse that powers the resistor should also be checked.
fan on my furnace will not shut off. smash it up then
If the electrical power is shut off to ANY electrical motor, it stops running.
the fan should run after car is tuned off until engine the temp is down ,then it the fan should shut off