HRLV MaxSonar EZ - Value does not change

We have been testing a HRLV MaxSonar EZ sonar sensor
using the Pin 3 analog voltage output. The sensor is connected
to the RoboRio Analog Input.

We setup the sensor 2’ away from a cinder block wall and it gave
us a reading of ~ .410 as we moved the robot back a foot, very little
change in value. Moving back to 10 feet, again no change in value.

We we just looking at the voltage output.

Is there a better pin to use to get this working?

Our next step is to connect it to a volt meter .

Thanks in advance.