Cooling System: Description and Operation

How the Circuit Works

Battery voltage is provided at all times to the radiator fan relay contacts through fuse 10 (in the under-hood fuse/relay box), and battery voltage is also provided at all times to the A/C condenser fan relay contacts through fuse 11 (in the under-hood fuse/relay box). The relays and the fuses are located in the under-hood fuse/relay box.

With the ignition switch in ON (II), battery voltage is supplied to the fan control relay coil and the A/C condenser fan relay coil through fuse 10 (in the under-dash fuse/relay box). The ECM/PCM controls the ground for both relays.

In extremely high coolant temperature conditions or customer A/C request, the ECM/PCM grounds the A/C condenser fan relay coil and the Radiator fan relay coil. Battery voltage is provided directly to the A/C condenser fan motor through fuse 11 (in the under-hood fuse/relay box) and to the radiator fan motor through fuse 10 (in the under-hood fuse/relay box). Both fans will run at full speed.