clacking noise from ac blower works but no air from dash

Service information stats that the dash needs to be removed to replace the mode door actuator on your 2003 Cadillac Deville. I would guess 5-6 hours labor.

Try checking prices on the internet. I use Rock Auto .com. I have no affiliation. I use them becasue of quick delivery and good prices. go to rockauto.com or click this link then follow the button and choose your year and make and model. You already know the name of the part so look under cooling or hvac parts.