AC/Heater will not change from regular air flow to feet/bilevel/defroster

What is your question?

I was turning my car on the other day...As I turned the key and the accessories came on before I started car I heard a thud noise...then, when I started the car the AC/HEATER still works BUT it wont alternative from normal air flow, (coming staight at you)to bi-level or feet or defrost.