Nissan Repair: 01 Altima engine, altima gxe, temperature switch

Question
Mr. Sudderth,
I just purchased a 2001 Altima GXE with 54,000 miles.  I noticed that every time I turn the car off and get out, the fan inside the engine compartment runs for a minute or so.  I live in New Jersey, so it's not exactly hot or even warm outside, but it appears to run regardless of ambient temperature.  While running, the engine temperature is normal.
Is the fan supposed to every time the car is turned off or is this a problem?
Thank you.

Answer
Yes, the fan can run after the engine is off.  But, it sounds like the relay to the fan is getting old and the contact points are sticking.  If it were me I would change the fan relay to see if it corrects the problem.  The relay is the inexpensive way to diagnose the problem.  If you are throwing parts at a problem you start at the cheapest one.  In you case there are two items that can cause the issue.  The first is the relay and the second is the temperature switch that commands the relay.  The relay is cheaper so go with it first and if that does not correct the problem get a temperature sensor that signals the relay.  The issue here is one of these days the fan is not going to turn off and your battery will eventually run down.  So, I assume you do not want to wait and see if the fan is going to turn itself off each time you get out.  A relay goes for under $20 bucks and is easy to replace.  The temperature sensor is a little more difficult and more expensive.