Z MIN PROBE USES Z MIN ENDSTOP PIN -- confusion.

I am having a bit of a time understanding how this should be setup.

First I'm using a RAMPS 1.4 / Arduino Mega 2560 combination.
I'm using Marlin 1.1.0-RC6.

I have an inductive probe plugged into the Z-min pins of the RAMPS board.
The probe is working normally, triggers when next to metal and otherwise open,
as shown with the M119 command.

I am using 2 Nema 17 motors to drive the Z axis. I have checked and both
motor cables are plugged in the same orientation, and they do turn the same way.

My problem is that I don't get any movement out of the motors.
When I go into the menu system to the Move Axis command,
and try to get the Z axis to move all they do is hum. No matter which
way I ask them to move. I did check to make sure that the inductive probe
was not triggered when this happens.

Could I have missed a setting that may be causing this?

Thank you