2003 GMC Safari Owner's Manual - Page 147

Outlet Adjustment Operation Tips 1. Clear away any ice, snow or leaves from the air inlets at the base of the windshield that may block the flow of air into your vehicle. 2. Use of non-GM approved hood deflectors may adversely affect the performance of the system. 3. Keep the path under the front seats clear of objects to help circulate the air inside of your vehicle more effectively. Move the thumbwheel in the center of the outlets up or down to change the direction of airflow. 3-22