My brother-in-law has a Kenmore washing machine that is driving us nuts. It will fill with water, but then won’t do anything but emit a loud hum regardless of the timer setting. Before I got involved with it he replaced the timer but that didn’t change anything. So, we removed the motor to check for a clogged pump or a stuck transmission. We didn’t find any obvious problems, so after we removed the motor we reconnected the wiring harness to it while it was laying on the floor, jumped out the lid switch and put power to it. It emitted a hum, but wouldn’t spin unless we spun the shaft & then it would turn slowly. We assumed the motor was bad & ordered a used motor.
We installed the new motor & it still is acting just like it was before. We are stumped. It is possible that both the original and the replacement motor are bad, but I don’t believe in coincidences, so what else could cause the motor to hum , but not run in any timer setting?
A faulty start capacitor can prevent the motor from starting which will cause it to just hum. Normally, you could rotate motor shaft by hand to get it started but you say it will only spin slowly if you do that. Try spinning the shaft faster. If motor won’t get going at normal speed then I don’t think it’s the capacitor. May be bad wire or terminal at motor harness connector. Check for corroded or burned terminals in connector. Pull on wires at connector to see if any are broken. Check voltage at motor connector between blue and white/black wires, should be 120vac. Don’t leave motor humming except for quick testing as it can damage the capacitor and motor windings. Inspect capacitor for cracks, bulges or loose terminals. Capacitor is on inside of back panel near water inlet valve.
http://www.appliancepartspros.com/whirlpool-capacitor-8572720-ap3861916.html
Eric