I have a Kenmore dishwasher, model #665-17795790, that won't drain after either the rinse or wash cycles. I have taken the machine out of the counter, and removed the outlet hose, checked it for obstructions (none), and even run a stiff wire down the copper drain tube that empties into the main sink drain pipe. Couldn't find any obstructions. I even reconnected the drain hose and blew through it, and it seems to be clear. A friend suggested the pump may be bad. I'm stumped. What do you think?