In a direct-acting valve, electric current activates the solenoid, which in turn pulls a piston or plunger that would otherwise block air or fluid from flowing. In some solenoid valves, the electromagnetic field does not act directly to open the conduit.
We hear so much about the hot starter syndrome that we are tempted to assume it's that problem right away. It still could be, but I once laid on my back in freezing weather changing the starter motor only to have the new one click too. I cleaned the terminals and everything was fine. I bought an unnecessary starter motor. Jan 09, 2012 Simple, step-by-step instructions for correctly shimming an automobile starter. Includes shimming tips and advice for all levels of auto repair experience, including DIY. Sponsored by BBB.
In pilot-operated valves, a solenoid moves the plunger, which creates a small opening, and pressure through the opening is what operates the valve seal. In both types, solenoid valves require a constant flow of electrical current to remain open because once the current is stopped, the electromagnetic field disperses and the valve returns to its original closed position. Electric Solenoids. In an automobile ignition system, the starter solenoid acts as a relay, bringing metal contacts into place to close a circuit. The starter solenoid receives a small electric current when the car's ignition is activated, usually by the turn of the key. The magnetic field of the solenoid then pulls on the contacts, closing the circuit between the car's battery and the starter motor. The starter solenoid requires a constant flow of electricity in order to maintain the circuit, but because the engine is self-powering once started, the solenoid is inactive for most of the time.
Uses for Solenoids.