Cooling System: Description and Operation

How the Circuit Works

Voltage is provided at all times to the radiator fan relay contacts through fuse 4 (in the under-hood fuse/relay box) and to the A/C condenser fan relay contacts through fuse 1 (in the under-hood fuse/relay box). With the ignition switch ON (II), voltage is provided to the coils of the relays through fuse 14 (in the under-dash fuse/relay box).

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

Voltage is also provided at all times to the hot restart fan relay contacts through fuse 14 and fuse 60 (in the multi-fuse/relay box). The hot restart fan relay is grounded by the ECM during certain conditions, allowing the radiator fan motor to run by itself.