Help! Loud clanking and whirring from under the fridge!

Saturday, I decided to defrost my Dometic refrigerator. Last time, it was quick and simple. Before going to bed, I turned it on a "Auto" and went to sleep. I awoke two hours later to a loud clicking and whirring sound coming from under the fridge. It is blowing cool air from a floor vent nearby, but the fridge itself is room temperature. I turned off the fridge, but the sound and the cool air continue. What could it be? How do I make it quit? I don't know how to get under there in the dark. I don't know how to turn off all power to make it quit. I don't know much of anything, and 12:40 am Sunday and I have no one to call.

I live in a 2016 Coachman Freedom Express 257BHS