2015 4.3l. Why do electric fans run continuously?

On most modern vehicles the engine cooling fans are electric. These fans are thermostatically controlled and will continue to run even after the vehicle is turned off and until the engine cools down. If you feel the fan is running an excessively long time after you turn off the vehicle, I would recommend you have it looked at by the dealer.
Good luck.

A significant number of cars have an electric cooling fan supplied by a battery live rather than an ignition live because it is believed the cooling fan should be able to start or to continue running after the engine has been switched off.
Coolant will continue to circulate after switch-off due to thermo-syphon activity and it could reduce mechanical stress on engine components to continue cooling.

Some people modify the cooling system by fitting an additional manual switch to over-ride the thermal switch for use when standing in traffic, for whenever continuous operation is desired or to use in emergency should the thermal switch operation fail.

In the absence of such a modification that has been inadvertently switched on the fault will be due to a faulty thermal switch, a faulty or stuck relay or shorted wiring. Disconnecting the thermal switch should stop the fan and if it does it indicates the switch is faulty. The switch is mostly fitted into the radiator header tank but sometimes is fitted to the bottom tank or the thermostat housing.

This is normal. Cooling fans today are not turned by the fan belt but are run by an electric motor. The fan continues running until the coolant temperature is reduced

sounds like the fan solenoid is stuck. or keep in mind when defroster is on or any climate control in this car the ac compressor will run .wich in turn will kick on the electrick fan .try it with the climate control completely off. let me know

Some vehicles have sensors that can control the electric fan with the ignition off to keep the heat buildup that naturally occurs right after turning off the engine. This can prevent hard starting that can happen with a hot engine. If it is doing this an abnormal amount, the sensor that is operable with the ignition off may be failing. Before turning off the ignition, check to see if the engine temperature is pushing the 'red zone;' if it is, then the fan operation may be normal but your engine may be running hot.

Usually after driving, your rad fan can continue to run for up to 2 minutes after shutting off the car. It can even start up on it's own if it detects that the temperature of the engine is too hot (say if it's over 50 degrees celcius). The fan running for these several minutes should be of no concern. If it's staying on and not turning off for 30 minutes, then that is of concern

There are extra cooling pumps that some foreign cars have that run for a designated time after the engine is shut off. I had a Mini cooper made by BMW that had it. If you hear it running for a while, but then it shuts off, thats normal. If it stays on for ever and never shuts off, I honestly don't know what to tell you

Check the fan relay, probably in fuse box in the engine compartment. Check owners manual to be sure. I have seen these melt causing fan to run all the time.

why does the cooling fan start working as soon as i start the car and doesn't shut off until i turn off the car?