Coolant Temperature Switch

Coolant Temperature Switch Circuit (A/C Only):

PURPOSE
Allows the "A/C ON" signal to be transmitted to the ECU. Used to prevent engine overheating by eliminating A/C operation.


LOCATION
Mounted in the thermostat housing.


OPERATION
The Coolant Temperature Switch is a contact type switch. It is normally in the closed position. When the engine coolant temperature reaches 233 - 244° F (112 - 118° C) the switch will open interrupting the signal to the ECU, the ECU will then cut power to the A/C relay until engine temperature drops below the 233 - 244° F (112 - 118° C) level.