Review on 4Inch Normally Closed Electric Solenoid Hydraulics, Pneumatics & Plumbing by Jeff Labore

Installed 2 of these on my car to activate the air release valve. Knowing so little about inductive loads at the time of purchase, I was surprised when my car stalled when the power went out. I didn't know that at the time, but the collapse of the magnetic field in an inductive load sends an UNCOMFORTABLE surge of voltage into your electrical system. I added a diode between the positive and negative terminals when I reconnected it and never saw the problem again. All the time they worked as expected with no issues.