The cooling fan runs at high speed from the minute the key is turned on and continues approx 6-10 seconds after car is turned off.
I have repaired many glitches through the years thanks to this forum but everything I have tried has failed so am hoping for new ideas.
what I have done so far,...
new thermostat
new battery
recharged ac
new fan relay ( all were from China and I was told they were junk so am on my 3rd one)
new fans, the twin fans in front of engine.
checked all fuses
I understand it will cycle and in extreme heat may run longer after car is shut down but cold in the morning? I might add it is loud and gets unwanted attention. Please help

 

It may be wrongly reading engine and/or ambient temperature sensor(s).

 

Blondie, humor me and before you start the car, turn off the dash heat-A/C (specifically, the A/C and defrost). Do the fans still come on? If no, what you are seeing is normal operation of the fans as the fans will run most of the time the A/C system is used. Yes, the A/C system is used during the defrost mode to dry the air to help pull the moisture off of the windshield.

If you are still having issues, let me know and we can take things from there.

 

Or I might add = the "automatic" climate button (it does the same thing as Thermo said in turning on A/C to dehumidify.