Calais V6-3300 3.3L MFI VIN N (1990)
Air Conditioning Switch: Description and Operation
This signal indicates that the A/C control switch is turned "ON" and the pressure switch is closed. The ECM uses this signal to adjust the idle speed, and
on some models engages the A/C compressor clutch. If this signal is not available to the ECM, the engine Idle may be rough when the A/C compressor
cycles. In some cases the A/C compressor will be inoperative.