The float switch is typically located below the float assembly at the bottom of a dishwasher's tub and is connected to the dishwasher's float. The mechanism of the float assembly is dependent on the level of the water in the tub, which acts as the float switch's trigger.
The float switch can generally be accessed by removing a kickplate panel below the door to the dishwasher. This panel can be opened by unscrewing several screws on the outside and inside of the dishwasher. The dishwasher door needs to be closed prior to removing the panel. Typically there are two wires which are connected to the float switch with slip-on connectors.