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Home >> Subaru >> 2005 >> Outback F6-3.0L >> Repair and Diagnosis >> Relays and Modules >> Relays and Modules - Cooling System >> Radiator Cooling Fan Motor Relay >> Description and Operation
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Radiator Cooling Fan Motor Relay: Description and Operation

Cooling Circuits

The cooling system operates in three different phases depending on the temperature of the engine coolant.




- 1st phase (thermostat closed)
When the engine coolant temperature is below 80 degree C (176 degree F), the thermostat remains closed. The coolant flows through the bypass and heater circuits. This permits the engine to warm up quickly.
- 2nd phase (thermostat open)
When the engine coolant temperature is above 80 - 84 degree C (176 - 183.2 degree F), the thermostat opens. The coolant flows through the radiator where it is cooled.
- 3rd phase (thermostat open and radiator fan operating)
When the engine coolant temperature sensor sends a signal indicating a temperature above 91 degree C (196 degree F) to the ECM, it causes the radiator fan (or fans) to operate.
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