Marquis L4-140 2.3L VIN A 1-bbl (1986)
Thermostatic Air Cleaner Vacuum Switch: Description and Operation
Air Cleaner Temperature Sensor
The sensor is installed in the cleaner tray and is subjected to temperature changes within the air cleaner. At a given increase in temperature, the sensor
bleeds off vacuum, permitting the vacuum motor to open the duct door to allow fresh air in while shutting off full heat.
