Wawa:
Just saw the diagram in post#5.If correct, then connect a (~4k7) pull up resistor between Arduino pin and Arduino 5volt.
And connect the sensor output directly to the Arduino pin.If this sensor is also connected to another unit, then only use a (~4k7) resistor between sensor output and Arduino pin. No internal pull up on the pin.
Leo..
the only problem is that the second input that the sensor is connected to has an internal pull up to 12 volts nothing i can do about it, so i am forced to use a resistor or something of the kind to limit power to the arduino, and i am unsure of the model helping a buddy out and its not really important.