Ac only blowing through defrost vent and not coming out of the main front vents. Please help

What is your question?

My tundra ac is working but it only blows through the defrost vents. The main vent of the vents that faces the passengers blows out nothing. The speed of the ac works. The heat also works. I check my cabin filter, replace the ac control knob or panel and still nothing works. when changing from ac blowing to the face and leg to defrost u can here it switch but no ac comes out of the front vents. Also when turning on the truck and turning on the ac unit it takes about 30-45 seconds for the ac unit to start running. Also after turning off the ac u it and car I can here a cranking sound under neath the dashboard. Please help thnx

What makes this problem better or worse?

Noyhing

How long has your 2007 Toyota Tundra had this problem?

Since I bought it from the old owner like 4/5 years ago