Our Kenmore dishwasher worked well for several months. Then the top tray started cleaning hardly at all and the bottom tray did not clean well. Sometimes detergent remained in the dispenser.

I placed a TV camera inside the dishwasher and looked at the top tray. The arm was not spinning and some water was dribbling down just from the arm's rotation joint.

Disassembled upper tray tubes, cleaned bottom filter, etc as often recommended but no improvement.

Thought maybe it was not filling with enough water. Yesterday added hot water before the cycle started. Cleaning seemed normal including the top tray so the water level is probably the problem.

What valves, tubes, sensors, floats, electronics, might cause the dishwasher to not fill with enough water?

Kenmore does not supply a repair manual. Where can I get a repair manual for the equivalent/similar Whirlpool dishwasher. What Whirlpool model is/might be closest to my Kenmore (purchased in 2010)?

Why too little water?

The shut off water on the supply line was only opened about 1/4 turn!

I believe that I had replaced the original valve handle with a spare aluminum one. It was probably a little over sized for the square valve shaft and the aluminum broke where it fit around the shaft, but it seemed OK. When turned to open it provided resistance as it slipped on the shaft but the valve was not opening.

Over a year of the dishwasher's not working and my trouble shooting it.......including putting a video camera inside the dishwasher to see the wash action ...........what can I say?

If your dishwasher is not cleaning properly especially in the top rack look inside the dishwasher after it fills - at the very beginning of the cycle. Water level should be across the bottom up to the edge of a float (on the right in my DW). If not, investigate water level.