Cooling System: Description and Operation
DESCRIPTIONThe cooling fan system consists of a two-speed cooling fan motor and a constant control relay module. The constant control relay module contains three relays: the EEC power relay, the high speed fan relay and the low speed fan relay. It also contains a solid-state transistorized relay that controls the A/C compressor clutch.
OPERATION
The Powertrain Control Module (PCM) monitors coolant temperature, vehicle speed, and A/C status to determine the speed at which the fan will operate. Once the fan speed is determined, the PCM energizes the high speed fan relay or the low speed fan relay applying battery voltage from fuse link B to the corresponding windings of the cooling fan motor.