How do you know if the capacitor not the blower motor is bad on the central air unit inside the attic? This is not the compressor outside just the blower unit indoors.

Is your blower humming and not turning. Do you know what the capacitor looks like and where it is located? If so do you have a multi meter that reads microfareds? Is the capacitor domed? If it is domed it is bad.Disconect the wires from the copacitor put both leads from the meter on each terminal. Is it is a 7.5 microfared capacitor with the meter set to mf you should read 7.5.