Cooling System: Description and Operation

How the Circuit Works

Voltage is provided at all times to the radiator fan relay contacts through fuse 57 (in the under-hood fuse/relay box) and to the A/C condenser fan relay contacts through fuse 58 (in the under-hood fuse/relay box). The radiator fan control module controls power to the coils of the relays.

The radiator fan control module is supplied battery voltage at all times through fuse 13 (in the passenger's under-dash fuse/relay box). When the ignition switch is ON (II), voltage is also supplied to the module through fuses 3 and 6 (in the driver's under-dash fuse/relay box).

The relays are grounded by either radiator fan switch A, B or the PCM. Grounding the relays energizes their coils and applies battery voltage to the radiator and condenser fan motors. Both fans then run until ground is removed from the relay coils.

If the engine coolant temperature is more than 212 °F (100 °C) when you turn the ignition switch to LOCK (O), the radiator fan control module will turn on the radiator tan and let it run for about 15 minutes.