Why does the fan only start working at the third speed setting but not the first?

[ValerieLynn]

Fan not operating at the first speed setting but only starting at the third speed is caused by a decrease in the capacitance of the fan starting capacitor. Replacing it with a capacitor of the same capacity will resolve the issue. Below is relevant information about automotive cooling fans: 1. Axial fans: The blades of an axial fan push air to flow in the same direction as the axis. The impeller of an axial fan somewhat resembles a propeller. During operation, the majority of the airflow moves parallel to the axis, meaning along the axial direction. The power consumption of an axial fan is lowest when the inlet airflow is free air at 0 static pressure, and it increases as the back pressure of the airflow rises during operation. 2. Centrifugal fans: When a centrifugal fan operates, its blades push air to flow in a direction perpendicular to the axis (i.e., radially). The intake is along the axial direction, while the exhaust is perpendicular to the axial direction.