The next thing I suspect is the mode door actuator is likely not getting the airflow actuators fully in position. Are you able to change airflow directions normally?
I ask because the actuators are engine vacuum actuated rather than electric. If the vacuum supply is weak or nonexistent, the doors will not move correctly.
If you look behind the controller, you will see a purple vacuum hose. Make sure it is fully connected and not leaking. That is the supply hose from the engine. If it appears good, remove it and start the engine. Place your finger over the end to confirm there is a good vacuum supply.
I attached the vacuum schematic below. Try this and let me know what you find. Also, with the engine running, see if you notice any hissing which could indicate a leak and note anything that appears disconnected.
See pic below.
Tuesday, December 6th, 2022 AT 1:56 PM