I'm trying to use a flow sensor to get PWM feedback to be received by a microcontroller. To test the sensor, I've wired the following to get feedback on an oscilloscope so I can get a feel for how the frequency adjusts based on the flow rate.
When I wire the flow sensor (the other grey sphere is a temperature which I haven't started on yet), the oscilloscope does not change voltage or frequency (solid line at 7V) when I have water flow through it. I've adjusted this circuit so that the resistor is in different places (I'm new to this thing so I figured I was doing something wrong) but at this point I'm not sure what I'm doing wrong. Is there some glaring problem I've overlooked or is this part just possibly broken?

When I wire the flow sensor (the other grey sphere is a temperature which I haven't started on yet), the oscilloscope does not change voltage or frequency (solid line at 7V) when I have water flow through it. I've adjusted this circuit so that the resistor is in different places (I'm new to this thing so I figured I was doing something wrong) but at this point I'm not sure what I'm doing wrong. Is there some glaring problem I've overlooked or is this part just possibly broken?