Sometimes my Efans won't turn off. I have to put the key back in and turn it to the on position for a second pull the key and wait to see if they turn off. That usually works. It only happens maybe once a month. They worked fine for over a year. I think I have them set to turn off when the ignition is turned off. I ran into the store once and came out and they were still running. It was like 2 or 3 minutes. LOL
They are 05 fans with the Nelson harness.
Thanks,
Mike

 

Could be a stuck relay. Can you pull the relay and test it? Hit pins 85 and 86 with a 9 volt battery and verify that it clicks on and off with no hesitation.

 

shanesSS's truck does this too at times? nelson harness with 05 e-fans too.