I have an older Kitchenaid dishwasher and the bottom always has about a gallon of water at the end of the cycle. This problem is not addressed in the little manual it came with. Is something plugged? Is a pump not pumping?

Any help much appreciated!

It's fixed!

I read the manual and also this web page.
Why won't the dish water drain? : APWagner.com Appliance Parts

I checked the drain hoses, but they looked normal. Then I checked the air gap at the sink and found it had some junk clogging it. Removed the junk, and the machine drained fine the next time!

Yay. I don't have to spend big bucks on a new dishwasher or new drain pump.