My ac is a goodman cpkj30-1ab. The condenser fan comes on every once in a while. I put a high velocity fan on top so I could keep using the ac. It looks to have 3 capacitors on it. One says hard start. The other is tall and round and the other is short and oval. My question is which is the capacitor for the fan.

On the side of the fan motor should be a wiring diagram. Trace the wires from the fan to the capacitor. If there are 3 wires, 2 should go to the capacitor and one to a line. The line may be directly from a contactor, and the capacitor will have a line from the contactor and another that is common. Hope this helps.