What is the best test to determine a faulty solenoid?

Measuring the voltage at the solenoid is the most effective way to determine if it is functioning properly. When troubleshooting irrigation systems, a solenoid operates using electrical power to open or close a valve. If the solenoid is receiving the correct voltage, it indicates that the control system is sending the signal appropriately, which means the issue may not lie with the solenoid itself.

If the measured voltage is absent or lower than expected, it signifies a problem, either with the solenoid or the control wiring leading to it. This method allows for a precise assessment of electrical functionality and aids in isolating faults more effectively than visual inspections or other methods. Other approaches, such as visually checking for damage or running the system, may not provide definitive information about the solenoid’s operational status. While these methods offer some insights, they lack the direct electrical measurement that is crucial for accurate diagnosis.