When testing solenoids, which sound should you listen for?

• A. Click
• B. Buzz
• C. Hum
• D. Rattle

Answer: (A)

Solenoids move a plunger with a quick magnetic snap when the coil is energized. That rapid movement produces a sharp, brief click as the plunger reaches its actuated position, so listening for that click confirms the device is actually moving and working. A persistent buzz or hum means the coil is energized but the plunger isn’t moving normally, often due to electrical or mechanical binding. A rattle usually comes from loose parts after movement, not the immediate actuation sound. If you don’t hear a click when power is applied, check the coil, supply, and any mechanical binding.