1994 GMC Suburban Owner's Manual - Page 146

Fan Control Button This button is in the upper right corner of your system control panel. The fan has four settings - low, medium low, medium high and high. Press the top of the button (+) to increase the air flow. Press the bottom of the button (-) to decrease the air flow. The setting you select is shown on your display as LOW, MED LOW, MED HI or HI. OFF Button Press this button to turn the air conditioning/heating system off. Pressing OFF will erase the present mode of operation from the system's memory. Outside airwill still come out of the heater outlet whenever the vehicle is moving forward. If the OFF button was pressed, you must press A/C, MAX, or one of the BLEND buttons for the system to come back on. Rear Air Conditioning and Heating Systems (Wagon Models) If your vehicle has either orboth of these systems, you can increase and decrease the air flow at the rear vents. Depending on the system you have and the setting selected, you can send cooled or heated air to the rear of the vehicle. Rear Air Conditioning (Without Rear Heater) If your vehicle has rear air conditioning (without rear heater), the controls are located above the front and second seats. The front and rear overhead controls let you increase and decrease the air flow at the rear vents. Front Control Rear Control 3-8