Auto Service 101: What A Solenoid Is, What It Does, And How To Recognize When It Needs Repair Or Replacement

11 May 2016
 Categories: , Blog


There are so many components to the typical gas engine that help it go. The engine alone is not enough to make your vehicle move, nor is the battery, the gas, or the ignition. In fact, if you are just learning about cars and trucks right now, you may be surprised to learn about all of the parts that get your vehicle started and keep it moving. One such part that is not often talked about is the solenoid. Here is more information on what a solenoid is, what it does and how to recognize when it needs to be repaired or replaced. 

What a Solenoid Is

The most basic definition of a solenoid is, "a device that converts energy into linear motion." Inside a car, a solenoid is found inside the starter itself. The starter would not be able to work without the solenoid, since the solenoid collects the energy channeled into it after the starter turns the vehicle on. If you were to locate and remove the starter, and then remove the solenoid, you would probably find what looks like a metal cylinder with a singular plunger end. It does not look like much, but it plays a very important part in getting your vehicle to move and stay moving. 

What a Solenoid Does

When you place your key in the ignition of your car, you are attempting to ignite an electrical spark within. That spark travels in a circuit, from the starter to the alternator to the battery and back to the starter again. The solenoid inside the starter collects that electrical energy in the metal coils found within and begins converting it to linear motion. The conversion passes the linear motion on to the engine, the drive train and the wheels, which are controlled by you, the driver.

How to Recognize When the Solenoid Needs Repair or Replacement

As a general rule, a misfiring or malfunctioning solenoid refuses to be "tripped." Your car or truck may run fine when it is running, but when you turn the car off and then attempt to turn it back on, it seems like the starter just cannot turn over. The difference between the starter being the problem and the solenoid is that the starter will still continue to work, making noise while you attempt to crank the ignition, but the solenoid just will not fire. If you can also get your vehicle started after a couple of attempts and the rest of the engine is running fine, this is a good indication that you should probably have your solenoid repaired or replaced (by auto repair service professionals) as soon as you are able.