2005 Cadillac STS Owner's Manual - Page 184

The recirculation mode is cancelled when you enter defog mode. If you select recirculation while in defog mode, it will be cancelled after 10 minutes. If you have fogging on the side windows, remain in defog or defrost mode until they clear. 0 (Defrost): Pressing the defrost button directs most of the air to the windshield, with some air directed to the side windows and outboard panel outlets. In this mode, the system will automatically turn off recirculation and run the air-conditioning compressor, unless the outside temperature is at or below freezing. Recirculation cannot be selected while in the defrost mode. This mode may also cause the fan speed and air temperature to increase. The rear window defogger will turn off about 10 minutes after the button is pressed, or if the vehicle's speed is above 30 mph (48 km/h), the rear defogger will stay on continuously. If turned on again, the defogger will only run for about five minutes before turning off. The defogger can also be turned off by pressing the button again or by turning off the engine. The heated outside rearview mirrors will heat to help clear fog or frost from the surface of the mirror when the rear window defogger button is on. Notice: Using a razor blade or sharp object to clear the inside rear window may damage the rear window defogger. Repairs would not be covered by your warranty. Do not clear the inside of the rear window with sharp objects. Rear Window Defogger The rear window defogger uses a warming grid to remove fog or frost from the rear window. The rear window defogger will only work when the ignition is in ON or during remote start, if programmed. See "Personal Settings Menu" under Vehicle Personalization on page 2-47 for additional information. Outlet Adjustment Use the lever located in the center of each outlet to change the direction of the airflow, either side-to-side or up and down. Use the thumbwheels to open or close the outlets to adjust the airflow. Turn the thumbwheel to the right to open the outlets completely and allow the maximum amount of air to enter your vehicle. Turn the thumbwheel to the left to close the outlets and minimize the amount of air entering the vehicle. = (Rear Window Defogger): Press this button to turn the rear window defogger on or off. Be sure to clear as much snow from the rear window as possible. 3-52