Arduino Mega and sensor voltage

[Wawa]

@qckslvr

The sensors have three wires... red is 12v pos, black is 12v neg, and white is a normally open switched leg.

The answer depends on what is on the white wire when the sensor is 'active/closed'.
It could be a connection to ground (NPN sensor) or a connection to sensor supply (PNP sensor).
Leo..