Trying to convert an A/C heater box to heat-only

I discovered the problem was that the heat and defrost door wasn't opening, so no air was blowing over the heater core. You do need to block off the big hole that flows air over the evaporator core that I removed, or else all the air will take that route. Viewed from the engine compartment, the air has to flow up the fan housing outlet that branches out from the motor housing at an upward angle toward the driver's side. Now I just need to figure out why the door is not opening.