Compressor Clutch Controls (RWD)
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 1998 GMC Suburban, 1998 GMC Pickup, 1998 GMC Cab & Chassis, 1998 GMC C3500 HD, and 1998 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
The A/C clutch relay is controlled by PCM. The PCM improves idle quality by delaying compressor clutch engagement until idle speed is increased, or disengages compressor clutch when idle speed is too low. Compressor clutch is cycled by PCM. The PCM smooths cycling of compressor clutch by adding fuel the instant compressor clutch is applied.