How do you recharge the AC on a 2003 GMC Denali?

To recharge the AC on a 2003 GMC Denali, first, locate the low-pressure service port, which is typically found on the larger diameter aluminum line. Attach a refrigerant can with a pressure gauge to the port and start the engine with the AC set to maximum. Open the valve on the refrigerant can and monitor the pressure on the gauge, ensuring it stays within the recommended range for proper cooling. Once the desired pressure is reached, disconnect the can and replace the service port cap.