cooling fans stay on so long that they drain my battery

[Scott Phillips]

Jeff. 

The switch; Sends a voltage to a relay and when the relay closes the fan starts. Your relay could be sticking or just in need of replacement. That would be the only condition where after the car is off, and you pull the plug on the switch would the fan continue to run.

Unless someone's been in there mucking in the wiring.

HTH..

Scott