Air Cleaner - Thermostatic: Operation: Notes
During engine warm-up, temperature sensor switch applies vacuum to vacuum motor. Air diverter valve is held in the "ON" position. Exhaust manifold heated air flows to air cleaner. As temperature of incoming air increases to 90°F (32°C), temperature sensor opens vacuum line to atmosphere allowing spring pressure to push valve to "OFF" position. Air now flows from outside, through air cleaner duct to carburetor.