To test a capacitor firstly we need a ohms meter. Now connect two probe of ohmsmeter to the capacitor's connector then observe the diflection if it deflect once and come back to the initial position then the capacitor is all right other wise its deflect but not come back or does not shows any deflection it capacitor is not ok.
discharge the capacitor(usually short the two leads with an insulated screwdriver),get a dmm (digital multimeter),set it to capacitor test,insert the leads where the dmm has markings for capacitor testing.
The best way is to use a multimeter with a capacitor testing ability. The meter will read a short one way and an open the other way since capacitor polarity matters.
Basic step is to test a capacitor with multimeter. This will used to find approximate UF ratings. Next we can take capacitor out of circuit and test with cap checker.
