Do they both do the same thing allowing adjustment of engine idle RPM when A/C is on? Is it just that the actuator/diaphragm uses vacuum and amplifier uses electronics to make the RPM change at idle?

Edit: I just read in another forum that the amplifier sets what RPM allows the compressor to kick on/off and does nothing with the idle. I'm confused since the amplifier does seem to change engine RPM when turning knob &then cycling the AC switch.

 

WHEN the A/C turns on, the idle is raised by the A/C idle up. To what? On the 22re only, you can adjust the increased idle at the VSV (not adjustable on the 3VZE).

When the engine rpm gets "too low," the A/C Amplifier shuts off the compressor. How much is too low? It's set on the amplifier.