Heater problem 84 300SD

[The Gears]

There is power to the mono valve but no ground from the Control Box
Also no power to the AC clutch when the Thermostat is on full cold.
The fan works OK but full hot air.
Am I missing something easy or do I have to pull the Control unit and do what.
Problem 2. Can the rear door swing stoppers or what ever they are called be serviced without removing from the door.
Mine are so stiff I had to undo them from the post.
Thanks