Check pressures on the a/c system. May just be low on refrigerant.

 

Even if it was low it shouldn't be coming on in the off position. I would check out the hvac switch first.

 

Funny story. Couple of days ago my truck would ding everytime I hit a bump. Sounded just like a hand bell. Was driving me nuts. Turned out the 3/4 drive socket set I had under the rear seat had popped open the box, and the sockets kept hitting each other.....