A/C question

It sounds as if your actual problem is a leaking or broken vacuum line. They run from the tree on the firewall, over to the passenger side, then through the firewall and up under the dash.

Inspect all those lines for a break or tear.

Your blower door is not being positioned properly. that's usuallythe result of the vac lines mentioned above. If all your line look good, checkout the vac operated actualtor under the dash on the passenger side to see if it's still good.