So last week after a long drive my cooling fan in the engine compartment would run after shutting the engine off, no problem just pulled the relay until I could get a replacement. The very next day I was driving home when the heater/AC blower in the cab came on in the high position, turn the blower to off it still runs at high turn it down to low still runs on high, I looked through the forums but could not find anyone else who had this issue, is it possible that the relay for the blower is gone as well.
2010 3.5l AWD

 

It sounds like you got water into the cabin or dash area
And it has shorted out a couple of things.
Just a guess.
Anyway, the HVAC blower is shorted out and blows on high
The resistor pack is by passed or shorted

Not sure what you can do to fix this short of replacing all the bad components and fixing that leak. (guess)