Now here’s where it gets interesting. For the most part, solenoid wires come wrapped around a metal rod. (The word “solenoid” is a derivative of the Greek word in solénoeidswhich means “pipe-shaped.”)
When the solenoid wire receives an electric current, this piece of metal will become attracted to — and get pulled toward — one end of the solenoid. But the effect of this immediate action on the solenoid is temporary. Cut off the electrical current the solenoid created, and you kill the magnetic field. Then, thanks to spring-loadingyour unit should revert back to its original position.
Basically, we can have our cake and eat it, too. A solenoid allows us to magnetize wires, creating a magnetic field, and then demagnetize them whenever we like (pretty much). All with the push of a button. Or the twist of a key.
Like we said before, cars use solenoids. Turning the ignition key relays electrical energy from your battery into a starter solenoid. Once the starter solenoid is activated, several things happen.
Electric current in the solenoid wire attracts a movable iron rod. The circuit between the starter motor and the car’s battery is completed. And a “pinion” gear wheel engages with a disc called the “flywheel.”
Within a couple of seconds, your once-dormant car engine comes alive. At least that’s how it’s supposed to work.
Has this ever happened to you? You’re sitting in your car and just turned the ignition key, but the engine won’t start. Instead, you hear an unpleasant clicking noise. The culprit might be a dead battery or a compromised alternator. Or perhaps your starter motor solenoid’s the real culprit here.
Any mechanic should be able to give your solenoid a test if (s)he’s got a circuit tester to test the circuit breakers or multimeter. Sometimes, these parts are fixable. Sometimes, they’re not — and need to be replaced. So goes the life of a car owner.