1999 Buick Riviera Owner's Manual - Page 147

yellowblue FRONT: This selection is used to defrost the windshield by directing the airflow toward the windshield. If FRONT is selected while in the AUTO mode, the fan speed and the air temperature from the front defroster will vary. If a manual fan speed setting is selected, the fan speed will remain at that selection until another fan speed selection is made or the AUTO mode is selected. To turn off FRONT, press the AUTO or AIR FLOW button. FRONT defrost will work better if any ice or snow is cleared from the hood and the air inlet area between the base of the windshield and the hood. system is in the AUTO mode on very hot days, the system will automatically enter the RECIRC mode and the temperature door will be positioned at the full cold position for maximum cooling. If the system is not in the AUTO mode, RECIRC should be selected to provide maximum cooling. You can choose the extreme comfort setting of 60_F (16_C), but the system will not cool any faster by choosing the extreme comfort setting. Heating On cold days, if the AUTO mode is selected, the system will automatically direct the air toward the floor and the temperature door will be positioned at the full hot position. You can choose the extreme comfort setting of 90_F (32_C) but the system will not warm up any faster by selecting the extreme comfort setting. If the outside temperature is cold, the fan will be delayed to avoid blowing cold air. Pushing the FAN, AIR FLOW or FRONT buttons will override this delay, turn off the AUTO mode and change the fan speed. Air Conditioning On very hot days, open the windows long enough to let the hot air out. This reduces the time required to cool the interior of the vehicle to a comfortable level. If the 3-5