[Big Ideas]

Don't forget to check the device.
use the solenoid valve manual override button to verify the valve runs normally. Then operate the solenoid directly with the proper voltage to verify the part is working. Most small solenoid valves must operate with a minimum pressure (15psi depending on device) because the actuator is "piloted" using air pressure assist. try attaching a different (or known good) solenoid and listen for electrical click when energizing. Then trace your wiring. Pay particular attention to the connectors and crimps, looking for loose connections.