I live in a rural area down a dirt rocky road with lots of potholes. I drove up my driveway last night to check the mail and hit a huge pothole. When I came back down the driveway and parked my car and turned it off, taking the keys out of the ignition, my A/C was still blowing (and hard!) and wouldn't shut off! I even turned the knob to "off" and it still wouldn't shut off. My car was totally off and the keys were out of the ignition. Needless to say, my car battery is now completely dead after having no choice but to leave the car like that all night.
My car has 130000 miles.
My car has an automatic transmission.
You may have shorted out the A/C blower resistor that controls the blower speeds. This component is supplied power all the time and only the switch controls the motor speed. If the resistor terminals where the resistors are touched together then it can cause the blower to run with the key in the off position. Have a new blower resistor installed and charge or jump the battery. I’d recommend you get the car looked at by a qualified mechanic who can diagnose your A/C issue first hand. If a mobile mechanic can’t make it out to you I suggest jump starting it and driving it to your local mechanic. Good luck.