Compressor (and Fan too, for that matter) use RUN capacitors. The one for the compressor would be around 45-mfd and the fan around 7.5-mfd. Forget the fan for now, it's working. A hard start kit (capacitor around 100-mfd and some kind of control device to get it out of circuit once compressor starts) may be ADDED TO the RUN (45-mfd) capacitor, but if the RUN capacitor is bad, the Compressor will sit in Locked Rotor Amps (LRA - marked on the compressor label). I would not give up on the compressor (and therefore the whole A/C) till the RUN capacitor is tested or swapped with a known good/new one.