Turn off power to the air conditioner at the breaker and disconnect
Verify power is off with a multimeter
Remove the access panel to reach the capacitor
Take a clear photo of all wire connections
Discharge the capacitor using an insulated resistor or insulated screwdriver with caution
Set the multimeter to capacitance mode if available
Disconnect the capacitor wires
Measure between the capacitor terminals
Compare the reading to the capacitor’s rated microfarads
Check for a reading within the capacitor’s tolerance range
If capacitance mode is unavailable, use the ohms setting and observe the needle or display behavior
Look for a brief low reading that rises toward infinity
Test each terminal pair on a dual-run capacitor
Check for signs of bulging, leaking, rust, or burn marks
Replace the capacitor if readings are out of range or if it shows physical damage