Air Cleaner - Thermostatic: Operation: Notes

When vehicle and outside air is cold, temperature of air entering the air cleaner is below the calibrated opening point of the air temperature sensor. Vacuum is not permitted to open the air valve to outside air. The air valve will close off the duct to outside air and only warmed air from the heat stove on the exhaust manifold will enter the air cleaner. As the exhaust manifold warms the air entering the air cleaner from the heat stove, the air temperature sensor begins to open, bleeding off vacuum to vacuum motor. The vacuum motor opens the air cleaner air valve, allowing outside air to enter the air cleaner to maintain temperature of air entering intake system.