Prizm L4-108 1.8L DOHC VIN 8 MFI (1998)
Radiator Cooling Fan Motor: Description and Operation
Engine Cooling Fan Description-Electric
RADIATOR FAN MOTOR CIRCUIT DESCRIPTION
The radiator fan motor will run at full speed once the engine coolant temperature reaches 93°C (199°F). With the ignition switch in ON or START,
voltage is applied to the coils of the engine main relay and the fan no. 1 relay through the ECU-IO fuse. Since the engine main relay is permanently
grounded at G103, it energizes providing battery voltage to the fan no. 1 relay. Since the fan no. 1 relay is grounded through the fan control switch, the
fan no. 1 relay energizes thus interrupting the current path to the radiator fan motor. When the engine coolant temperature reaches 93°C (199°F), the
fan control switch opens and ground is lost to the coil of the fan No. 1 relay. The fan no. 1 relay de-energizes applying voltage to the radiator fan
motor. Since the radiator fan motor is permanently grounded at G103, it runs at full speed. When the engine coolant temperature reaches 83°C (181°F)
The fan control switch closes thus providing a ground to the fan no. 1 relay. With this ground provided the relay energizes, the current path to the
radiator fan motor is interrupted, and the radiator fan motor stops running. The radiator fan motor will cycle on and off at full speed as the engine
coolant temperature increases and decreases.
