I own a 2011 Jaguar xf with 70k on it and recently the cooling fan started constantly running even after the car was off. I will also start running when I open the driver side door without the car being on. I checked the fuse box and the F17 cooling fan fuse(80a) is missing, could this be the reason? Mechanic said I need an entire fan assembly, but if the fan works why do I need the entire assembly? Any help would be great.

 

From the service manual:

The cooling fan is operated by a fan control module integrated into the cooling fan motor. The fan control module regulates the voltage, and thus speed, of the cooling fan motor in response to a PWM (pulse width modulation) signal from the ECM. The ECM calculates the required fan speed from the engine temperature, A/C (air conditioning) system pressure and transmission fluid temperature. Under hot operating conditions, the fan may continue to operate for 4 minutes after the engine has been switched off.

The signals may be observed using SDD.
Alternatively, Inexpensive phone app, TorquePro and wireless OBDII allows monitoring engine temp, etc.

As crazy as it sounds, the mechanic may be correct: primary mode of failure for fan motor is bearings. When they begin to fail, added drag on the motor may cause intermittent failure during "normal" operation.
Thus, need to run "after hours".
Easy to check: disconnect the battery (for safety), manually give the fan a good push. If it coasts very freely, good. If not, replace.

Also see: https://www.jaguarforums.com/forum/x...t-work-242928/
https://www.jaguarforums.com/forum/x...roblem-236657/
https://www.jaguarforums.com/forum/g...ng-fan-237086/
https://www.jaguarforums.com/forum/x...ing-fan-58807/

Add your location to your info. Also vehicle details. Makes it easier for folks to help you.
Are you in a warm or cold climate?

PS: If anyone has successfully disassembled the fan motor and replaced the bearings, please post a tutorial.