You can test the cap with a VOM.

Test the Motor Capacitor: attach the ohmmeter's leads to the capacitor's terminals, one pair at a time and check the reading on the ohmmeter.

Ohm reading drops to zero then slowly rises: the capacitor is probably serviceable

Infinite resistance: If the ohms reading stays at a very high value or at infinity then the capacitor has an open circuit internally and is probably shot. Replace the capacitor.

Low or zero resistance: If there is zero resistance (zero ohms) the capacitor is shorted internally. You are seeing low or no resistance, or very low ohms reading. This capacitor is no good. Replace this capacitor.

If you reverse the + and - leads of the DC ohmmeter it will repeat. If you do not see any resistance in the capacitor then it has an internal short and it's shot - you need a new one.