Riviera V6-231 3.8L VIN C SFI (1989)
Air Conditioning Switch: Description and Operation
This signal tells the ECM that the A/C selector switch is turned "ON," and that the A/C pressure switch is closed. The ECM uses this to adjust the idle
speed before turning "ON" the A/C clutch. If the signal is not available to the ECM, the A/C compressor will be inoperative.