If you re concerned that your furnace capacitor isn t operating properly you can test it by following a few simple steps.
Furnace blower capacitor test.
Bench or under load test.
A furnace usually uses a run capacitor to maintain a relatively constant voltage supply to the blower motor.
If the system is not running then a bench test will be the best bet.
Remove the wires from the terminal and discharge the capacitor using the instructions included with your furnace.
The capacitor will still hold a charge even without power.
Set a voltmeter to the x1 setting.
Shut off the power to the furnace at the fuse.
Remove the blower housing inside the furnace to access the capacitor.