[mtcosby]

Maytag dishwasher (2002 era) only fills with a small amount of water. Checked float level switch with ohm meter, functioning normally, can turn incoming water on or off with float switch but the washer turns the water off and starts the pump before there is enough water. I have to add two gallons of water to get the water level to the float switch. What now?

[magician59]

It sounds like the float is either sticking, obstructed, or otherwise out of adjustment.

[denman]

Here are your parts
Replacement parts for MAYTAG PDB3600AWX Dishwasher - Undercounter | AppliancePartsPros.com

On most units the float is an overfill protection device and does not regulate the water level normally.

Remove the water inlet valve and check that the screen filter on it's input is clean, could be you have a partial plug.
If dirty clean it and give it a try. Do not remove the screen permanently from the valve as it is there to keep crud out of the valve which could hold it open and cause a flood.

If the above does nothing I would replace the valve.