Furnace Blower Capacitor Test
If the system is not running then a bench test will be the best bet.
Furnace blower capacitor test. Decide if under load or bench testing is best. Set a voltmeter to the x1 setting. Shut off the power to the furnace at the fuse. Remove the wires from the terminal and discharge the capacitor using the instructions included with your furnace.
A furnace usually uses a run capacitor to maintain a relatively constant voltage supply to the blower motor. The capacitor will still hold a charge even without power. If you re concerned that your furnace capacitor isn t operating properly you can test it by following a few simple steps. Do not do an under load test on blower capacitors due to the risk of the meter leads around a spinning blower wheel.