2003 Hummer H2 Owner's Manual - Page 198
2003 Hummer H2 Manual
Page 198 highlights
Automatic Operation Press the AUTO button to set the system to automatically control the air delivery mode, fan speed, air temperature and recirculation operations. Pressing this button when the system is off will turn the system on. When AUTO is selected, the air conditioning operation and air inlet will be automatically controlled. The air conditioning compressor will run when outside temperature is over approximately 40_F (4_C). The air inlet will normally be set to outside air. If it's hot outside, the air inlet will automatically switch to recirculated inside air to help quickly cool down your vehicle. To find your comfort setting, start with a 74_ F (23_C) temperature setting and allow about 20 minutes for the system to regulate. Turn the driver's or passenger's side temperature knob to adjust the temperature setting as necessary. If you choose the temperature setting of 60_F (15_C), the system will remain at the maximum cooling setting. If you choose the temperature setting of 90_F (32_C), the system will remain at the maximum heat setting. Choosing either maximum setting will not cause the vehicle to heat or cool any faster. Be careful not to cover the sensor located on the top of the instrument panel near the windshield. This sensor regulates air temperature based on sun load. To avoid blowing cold air in cold weather, the system will delay turning on the fan until warm air is available. The length of delay depends on the engine coolant temperature. Pushing the fan switch will override this delay and change the fan to a selected speed. Air Conditioning On hot days, open the windows long enough to let hot inside air escape. This reduces the time it takes for your vehicle to cool down. Then keep your windows closed for the air conditioner to work its best. On cool, but sunny days while using manual operation of the automatic system, use bi-level to deliver warm air to the floor and cooler air to the instrument panel outlets. To warm or cool the air delivered, turn the temperature knob to the desired setting. In AUTO mode the system will cool and dehumidify the air inside the vehicle. Also while in AUTO mode, the system will maximize its performance by using recirculation as necessary. 3-6