Solving a front HVAC issue?

That sounds like a mode door controller problem. That system uses vacuum actuators that control the airflow. They get vacuum from a line that connects to the intake manifold and goes to a vacuum tank and then to the dash control assembly. As you cannot control any of it I suspect there is an issue with the main vacuum line. It is the only item that can stop all of them from working. The common thing is for the line to rot and leak so that you get no vacuum. You will likely need to remove the doghouse to get to the engine to find the vacuum line and trace it. With a cold engine you could spray some starting fluid or carb cleaner along the lines, when you find the leak the engine will rev.