2001 Ford Windstar Replaced Blend Door Actuator

Air conditioning was working but had clicking sound so we knew we needed to replace the blend door. We were dealing with it buy keeping the switch moved slightly to the right since the air was working ok. Then the air in the front stopped working, but kept working in the back. It's not super cold in the back but it is coming out cool. My husband replaced the blend door actuator thinking that this would solve the problem. This is the second one he replaced. Well the clicking sound has stopped but there still isn't air in the front. Any ideas of what is wrong?