Where is 2001 Sterling truck heater blend door?

In a 2001 Sterling truck, the heater blend door is typically located within the HVAC (heating, ventilation, and air conditioning) housing, which is usually situated behind the dashboard. To access it, you'll generally need to remove the dashboard or portions of the center console. The blend door controls the mix of hot and cold air to regulate the temperature inside the cabin. If you're having issues with temperature control, it may be necessary to inspect the actuator or the blend door itself for proper operation.