Z-Endstop (Inductor) not recongnized

I have wired an inductor according to the documentation so that when not near a surface I have a potential of nearly 5v between the ground of RAMPS and my signal pin. I plugged this pin into the S pin of the Z-Min endstop and I don't get any change in the digital state of the endstop in either of the inductors states. If I complete a circuit between the - and S pins then the digital endstop state changes. I'm kinda stumped. Any advice?

Let me see if I understand you. You have connected a inductive Proximity Sensor Up to a Ramps 1.4 or Ramps compatible Controller.

VCC +5 - Z-Min Pin Vcc
Signal - Z-Min Pin S
Ground - Z-Min Pin Gnd

Your printer model may come in handy.
And you had a end-stop switch in place that previously worked?
What model inductive proximity sensor are you using?

How was the end-stop switch wired?

Please post inductor documentation.