RechargE the air conditioning 1997 gmc?

To recharge the air conditioning system in a 1997 GMC, first, locate the low-pressure service port, typically found on the larger diameter refrigerant line. Ensure the engine is off and connect a refrigerant canister with a gauge to this port. Start the engine and turn the AC to the maximum setting, then slowly release the refrigerant while monitoring the gauge to avoid overcharging. Always check for leaks and ensure proper refrigerant type is used, as older models may require R-12 or retrofitted R-134a.