Wire identification

[Grandpa Hilljack]

I’ve got a few wires with plugs I’m trying to sort out. If someone could let me know if these are needed and what they are for I’d appreciate it.
The blue arrow has some sort of old burnt up switch on it.
The yellow circle I’m guessing went to a/c controlling?
Also, if I’m reading the schematic right, the 2wire switch bolted to the firewall (blue square) was a “tip in switch” so I shouldn’t need it. Is that correct?

I’m trying to get the heat controls to go to defrost and so far it’s only on heater. There’s a vacuum line coming out that isn’t connected.

 

[wlwarnke]

The orange circle (green wires) is the AC compressor clutch.

The damper inside the cab are actuated via vacuum. The source is the engine(duh) then it goes to a Tee. One leg goes inside the cab via a small hard plastic(usually) line that enters the firewall through a grommet right between the Evaporator case and valve cover. The other side of the Tee goes to the vacuum reservoir (black ball). There should also be a check valve between the Tee and the engine. Sometimes the Tee has the check valve built in. This check valve allows the dampers to work/hold position during full throttle (no manifold vacuum).

With your vacuum source disconnected, I believe the dampers default to the floor.