My dishwasher is not draining so I started taking some of it apart. Could not figure out how to undo the hex nut black thing just would spin. Do i need to hold it still with a one inch wrench while turnin the hex nut? I think it is clogged under there somewhere?.
The first thing I would check is the check valve (#15 on the break down diagram). Remove the drain hose from the check valve and unscrew it from the pump. Most likely there is a foreign object stuck inside.
Here are the break down diagrams for the Whirlpool dishwasher Model DU943PWKT0
Gene.