If the vehicle is equipped with air conditioning, refer to the HVAC Compressor/Condenser Fan Circuit Description in HVAC Systems with A/C-Manual.

With the ignition switch in ON or START, voltage is applied to the coil of the engine main relay and the fan no. 1 relay through the ECU-IG fuse. Since the engine main relay is permanently grounded at G103, it energizes providing battery voltage to the switch side of the fan no. 1 relay. 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 and the relay de-energizes. With the relay de-energized, voltage is applied to the fan motor through the switch side of the fan no. 1 relay. Since the fan motor is permanently grounded at G103 the fan motor runs. 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, interrupting the current path to the fan motor. It is when this happens that the fan motor stops running. The fan motor will cycle on and off as the engine coolant temperature increases and decreases.