Rear air started blowing and wont stop even when system turned off

Rear air started blowing and wont stop even when system turned off 2013 Ford Explorer. Rear air all of the sudden started blowing while I was driving even when entire system was turned off and rear control turned off. I have turned car off and back on. Same thing happens. I've turned air on hot and cold, up and down, and on and off but air still blowing hard through rear vents even with EVERYTJING turned to “. I”.