Remove the tubing form its fittings and then the fittings it connects to. Then poke a screw driver through the hole in the pump and up into the bottom of the switch (careful not to break the switch). Clean the fittings too. Pound a nail through the hole where the tubing fitting screws into the pump wet end if needed, just don't damage the threads. If all that doesn't get water to flow to the switch, you must not have water in the pump. Did you prime the pump?