To test a capacitor with a multimeter, set the multimeter to the capacitance measurement mode. Ensure the capacitor is discharged by shorting its terminals with an insulated tool. Connect the multimeter leads to the capacitor terminals—positive to positive and negative to negative. The multimeter will display the capacitance value of the capacitor. Compare this reading to the capacitor’s rated capacitance value. If the measured capacitance is significantly lower than the rated value or if the multimeter shows no capacitance reading at all, the capacitor may be faulty and in need of replacement.
To determine if a capacitor is bad using a multimeter, follow similar steps as testing for capacitance. Set the multimeter to the capacitance measurement mode and discharge the capacitor. Connect the multimeter leads to the capacitor terminals and observe the reading. A capacitor is considered bad if the measured capacitance is much lower than its rated value, indicating internal degradation. Alternatively, if the multimeter shows no capacitance reading at all, this suggests that the capacitor is open or has failed completely. Physical inspection for signs such as bulging, leaking, or a burnt smell can also confirm capacitor failure.
The symbol for capacitance on a multimeter varies depending on the manufacturer and model. However, it is commonly represented by the symbol “µF” (microfarads) or a similar abbreviation corresponding to the unit of capacitance. When in capacitance measurement mode, the multimeter display will show this symbol next to the numerical value indicating the capacitance of the component being tested, such as a capacitor.
To test if a capacitor is still working, use a multimeter set to measure capacitance. Begin by ensuring the capacitor is discharged. Connect the multimeter leads to the capacitor terminals—positive to positive and negative to negative. The multimeter will display the capacitance value of the capacitor. Compare this reading to the capacitor’s rated capacitance value. A capacitor is considered to be still working if the measured capacitance value falls within an acceptable range (typically within a certain percentage of the rated value, depending on the capacitor type). Additionally, observe the multimeter reading for stability; a fluctuating or unstable reading may indicate a faulty capacitor, even if the capacitance value initially seems correct.