Radiator Cooling Fan: Description and Operation

System Outline

System Operation
When the power SW is pushed to IG ON position (Power SW type), or when the ignition SW is turned to ON (Ignition SW type), the current from the HTR fuse is sent to the coil side and the FAN NO.1 relay is turned to ON. Then the current flows to TERMINAL 3 of the cooling fan ECU. At the same time, the conditions of the A/C SW, A/C pressure sensor, engine coolant temp. sensor and engine rotation are sent to the TERMINAL 2 as signals from front controller. As a result of that, the cooling fan ECU continuously controls the rotation of the fan motor and keeps a balance between the cooling efficiency and silentness with the optimal fan rotation.