System Operation

When the power SW is pushed to the IG ON position (Power SW type), or when the ignition SW is turned to ON (Ignition SW type), current from the HTR fuse is sent to the coil side and the FAN NO. 1 relay is turned to ON. Then 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 the front controller. As a result of that, the cooling fan ECU continuously controls the rotation of the fan motor and keeps the balance between cooling efficiency and quietness by optimizing the fan rotation.