Air Conditioning Switch: Description and Operation

This switch is a bi-metal snap action switch which senses engine coolant temperature. The switch is screwed into the heater water valve. It closes above approximately 95°F and turns on heater blower. When coolant temperature is below 95°F, the switch opens and the programmer will hold heater blower "OFF" until coolant temperature exceeds 95°F. When vehicle interior is hot and A/C mode is required, the programmer will override the switch and turn on blower immediately.