Engine Coolant High Temperature Switch
The air conditioning condenser is usually positioned in front of the engine cooling system radiator. The air conditioning system transfers heat to the air passing through the condenser, which then has to pass through the radiator. When the ambient temperature is high, the already heated air passing over the radiator is unable to carry away sufficient heat from the engine coolant, and engine overheating can occur.
To prevent the possibility of overheating, some vehicles are equipped with a coolant temperature switch that disengages the compressor clutch when the coolant temperature exceeds a predetermined level.