Air Cleaner Temperature Sensor
At an ambient temperature of less than 24°C (75°F), the sensor will allow vacuum to close the duct door to fresh air. The sensor will bleed off vacuum to allow the duct door to open and let in fresh air at or above the following temperatures:
Brown 24°C (75°F)
Pink, black, or clear 32.2°C (90°F)
Blue, yellow or green 40.6°C (105°F)