I think I've tracked my power steering leak to some type of sensor on the pressure line, close to where it connects to the steering box:
I assume this is a pressure sensor? I got no CEL or anything like that when the fluid had leaked down to the level that the pump started whining pretty badly though. As far as I can tell by looking at pictures, the parts store replacement pressure lines do not have this sensor, or any provision to connect a sensor to it: Advance Auto Parts: Power Steering Pressure Hose by Powercraft - Part 71878

Anyone run into this issue before? I may just put a replacement line on there and leave the sensor plug hanging and see what happens...

Thanks!