Pararrel Pots : very odd situation

What are you meassuring between ?

The centerpin on the pots and ???

If you want to use it with a analog in on the arduino board you should be meassuring Volts between the centerpin and ground. because the pots are wired as voltage dividers sending a voltage between 0 and 5 volts from the centerpin to an analog in pin on the Arduino board.

The wiring looks perfectly right.