My fan stays on after I shut my engine. This is not so bad since it has been extremely warm lately but sometimes it stays on until my (good) battery dies, which is bad.
There is a sensor on the radiator, if I recall correctly, that controls when to shut off the fan when the engine is off but I don't remember the exact name of this sensor.
Can I buy a replacement part from an auto zone type parts store?

 

Radiator Thermostatic Switch

The switch as it is not a sensor is on the left rear lower with 3 wires

There is a simple test to see if what the switch controls ( fan control relay module ) is stuck by water intrusion from the module hanging upside down

The black color X308 module does not work on the X300 as this one is white

There are 1 and sometimes 2 pressure switches ( depending if the TSB has been accomplished ) on the freon lines to command fan operation

 

The TSBs referred to in the HVAC and Cooling system circuits

 

I'll write out the test instructions in the morning to test the fan control relay module

The X308 with the V8 does use a temp sensor in the place of the X300 temp switch

Dr, day today

 

The fan should shut off about... 2-5 minutes after engine shut off. Not enough run time to kill a good battery. So there might be a problem. Your local auto parts store will not have the switch or the relay, but they can be bought online if needed.