My understanding is that the A/C compressor sends out a passive speed signal and it is upto the climate-control brain to compare the A/C compressor speed signal against RPM, and if the delta is too great the climate-control brain will disengage the clutch.

Which also means, if you don't have "brain" watching, the A/C compressor will just keep on pumping.

Please confirm.

BTW: if my understanding is correct, does this also mean that the pump when "on " is always 100% and doesn't use the speed-signal to vary pumping ?

Thanks,
:-) neil