Condenser Fan: Description and Operation

Radiator Fan


Voltage is provided at all times to the radiator fan relay (contacts) through fuse 33. With the ignition switch in ON (11), voltage is provided to the coil of the relay through fuse 13.

The radiator fan relay can be grounded through either the engine coolant temperature (ECT) switch or the engine control module (ECM).

The engine coolant temperature switch grounds the radiator fan relay (coil) when the engine coolant temperature exceeds 199 °F (91 °C). The switch opens when coolant temperature decreases 3°-8°C.


Condenser Fan


Voltage is provided at all times to the condenser fan relay (contacts) through fuse 35. With the ignition switch in ON (11), voltage is provided to the coil of the relay through fuse 13. When you push the A/C switch and put the blower switch in the LO, M1, M2, or HI position, and the A/C thermostat is closed, the condenser fan relay energizes, and the condenser fan motor runs.

As described on page 61-2, the condenser fan relay (coil) is grounded when an A/C request input is made to the engine control module (ECM). If the engine is running, the condenser fan will come on when you turn on the A/C system.

The A/C system will shut off if the A/C pressure switch or A/C thermostat opens. The A/C pressure switch will open when the A/C system high side pressure becomes too high or low. The A/C thermostat is normally closed, but will open when the temperature in the system falls below 35°F (-1.5°C).