Turn off power and discharge the capacitor fully
Remove the capacitor from the circuit if possible
Set the multimeter to capacitance mode
Connect the probes to the capacitor terminals
Read the capacitance value on the display
Compare the reading to the capacitor’s rated value
If the multimeter has no capacitance mode, set it to resistance mode
Touch the probes to the capacitor terminals
Watch for a brief low reading that rises toward infinity
Reverse the probes and repeat the test
Check for a short if the reading stays near zero
Check for an open capacitor if the reading never changes
Replace the capacitor if the reading is far from the rated value or unstable