Dishwasher will not drain ...kenmore ultra wash..goes through cycle but water stays in bottom

Failing to drain is either a blocked drain line or a broken drain pump. First check inside for blockages. When you first turn it on, you should hear a click and a whirring, that's the drain pump turning on. If you don't hear this, your pump is not working. To replace the pump you will have to order the right part, remove the front panel and install it. It usually goes in from the front, bottom, but it's much easier if you remove the DW and tilt it on it's back. It's a fairly simple install, 2 hoses, 2 wires, a few screws and it drops right in.

If you do hear the pump working, then you likely have a clog and you'll want to trace along the drain line to isolate and remove it manually.