Maytag Neptune won't drain

Hello, I've got an old maytag neptune mah3000aww, the drain pump sometimes works fine, other times won't drain at all. When it doesn't work I can hear a slight electrical hum but pump is not running. If I rotate dial around to spin cycle again , then pump will start and drain normally. Is this a bad pump or something else in control dial?
Thanks

via Maytag Neptune won't drain
by Farmerchad