The starter solenoid plays a crucial role in the ignition system of modern cars. Without it, the engine will fail to start. And yet, the importance of this small part is often overlooked. This is why I have prepared a comprehensive guide to your starter solenoid.
This article will help you learn how a starter solenoid works and how to locate it. Furthermore, it will teach you how to diagnose any issues that may affect the solenoid’s performance.
What Is a Starter Solenoid and What Does It Do?
This electromagnet is part of the car’s starter engine. Along with the battery and the starter gear, it initiates the ignition of the motor. But how does this happen?
The starter solenoid has two main functions. The first is to switch the start circuit on or off. It controls that process because it connects the starter to the battery.
Its second function is to move the starter pinion. That helps the latter engage with the flywheel ring gear. The result is the ignition of the engine.
As you can see, the starter solenoid is a small part of great importance. If it malfunctions, you won’t be able to start your car.
Where Is It Located?
It is vital to know the location of your starter solenoid. This information may help you fix or diagnose a faulty starter system. Also, it would be useful if ever you need to change or repair the solenoid.
In most cars, the solenoid is mounted onto the starter motor. So, you will need to locate the starter. But how do you do that?
First, find the battery and locate its positive terminal. Here’s a hint: it connects to a red cable.
Then, find the other end of that cable. It will lead you straight to the starter motor since it’s attached to it.
Take a close look at the motor. The starter consists of two cylinders — a small and a big one. The solenoid is part of the smaller of the two.
Other Parts of the Starter Unit
The performance of your solenoid often depends on that of other parts of the starter. They are all interconnected. When one of them fails, the rest follow. That’s why it’s important to know what the components are and what they do.
Starter motor: This is an essential part of the unit. Its function is to crank the engine so that it can start. It consists of:
- Armature
- Brushes
- Field coil
- Commutators
Motor housing: It shields the starter motor and its parts. That protects them from corrosive wear and rust.
Pinon: It helps the flywheel ring gear rotate. That process starts the engine.
Shift fork: It connects to the drive gear. The solenoid plunger moves it to rotate the drive gear.
Drive gear: It rotates the flywheel ring gear. That, in turn, engages the piston cylinders and starts the car.
Did Car Engines Always Have a Starter Solenoid?
The engines of most early car models did not have a self-starter. Instead, drivers had to use a hand crank to start their vehicles. The handle was set on the front side of the car. To start the engine, one had to rotate the crank many times.
The problem with this mechanism was that it was downright dangerous. The handle would start turning uncontrollably every time the engine backfired. That was a recipe for accidents. Many car owners suffered injuries in that way, and some even lost their lives as a result.
The manual engine-starting process required a lot of physical strength. This caused great inconvenience to the drivers of more powerful vehicles. Women, too, were unhappy with such a physically demanding task.
The hand crack trend slowly started to die out after the second decade of the 20th century. The cause for its “demise” was the introduction of self-starting motors. They were the first to incorporate solenoids in their composition.
Today, about a century later, the starter solenoid can be found in almost every car under the sun.
Diagnosing Starter Solenoid Issues
How Long Does It Last?
The motor starter and the parts that make it up tend to be rather durable. That is also the case with the solenoid. Some car owners experience issues with it once in a lifetime.
Still, like most other components, it can give out at any point in a vehicle’s lifespan. Even recently-purchased automobiles may have a bad solenoid.
What Causes Starter Solenoid to Become Faulty?
Your solenoid does not need to be old and worn-out to become faulty. Several factors can cause damage to it.
One of the most common causes of such a malfunction is over-tightening bolts. That can damage the solenoid and other components of the ignition system. Moreover, it may lead to a short circuit.
Faulty wiring can also lead to issues with the starter solenoid. If the wires are not connected properly, the risk of a short circuit will again be significant.
Be careful not to expose your vehicle to moisture. That can damage the solenoid contacts. When this happens, you will struggle to start the engine on the first try.
Heat is another “mortal enemy” of this car part. The solenoid can handle high current for a limited amount of time. After a certain point, the heat produced by this current melts its contacts, and the damage is done.
What Are the Symptoms of a Bad Starter Solenoid?
When your car’s solenoid is out, the entire ignition system is out, too. So, you will not be able to start the engine. That can be quite an inconvenience if it happens when you’re in the middle of nowhere, for example.
Luckily, there are four giveaway signs that your starter solenoid is not working. They include the following scenarios:
- The starter keeps running
- The starter makes a clicking noise
- The car takes several tries to start
- The vehicle does not start at all
Scenario #1
You start the engine. Then, depending on your car model, you stop pressing or release the key. Yet, the starter continues to run.
This problem occurs when the starter circuit is unable to close. Melted solenoid contacts usually cause that. Do not overlook this problem because it may also damage all other parts of the starter motor.
Scenario #2
Upon starting your car, you hear a clicking noise.
Such clicking may show that the solenoid is unable to send the current power. That means the starter relay fails to engage the starter motor of the engine. To solve this problem, you need to fix or change the solenoid.
Before you do that, determine how many clicks you hear. If it’s more than one, chances are there is something wrong with the electrical system. When you hear the clicking sound only once, you are dealing with a solenoid issue.
Scenario #3
Normally, your car starts in one attempt, but not this time. It takes you several tries before you finally manage to ignite the engine.
This is usually caused by faulty wiring, debris, or both. Check the starter for loose wires and dust. Sometimes, a poorly connected cable can get covered in dirt. That, too, may prevent the vehicle from starting on the first try.
Scenario #4
Try as you might, the car simply does not start.
Unfortunately, this is the worse “symptom” of a bad starter solenoid. The diagnosis, in this case, is grim. This vital component of the ignition system is damaged. You are not likely to get your car going.
But it may not be that bad! The other parts of the circuit may still be working. A clear sign of that is a single clicking sound. Hopefully, you will hear it when you try to start the engine.
Fixing Starter Solenoid Issues
Can You Jump the Starter Solenoid?
To jump a faulty starter solenoid means to direct the electric current to the starter manually. That may help you ignite the engine and get to the nearest auto repair shop when your solenoid gives out.
But beware! That is not a safe practice. It can damage the motor beyond repair. What’s worse, you may get yourself electrocuted.
Bypassing the solenoid is an emergency solution that you should avoid. Resort to it only if you have run out of options.
To jump the starter solenoid, you will need a helping hand and a screwdriver with an insulated handle and a long shank.
Start by shifting the transmission to neutral and engaging the handbrake. That would prevent the vehicle from moving while you are working on it.
Then, locate the starter motor and the starter solenoid. Look for two contacts. The jumper and starter wires are attached to them. They are connected to the engine bay and the starter, respectively.
Touch the contacts with the tip of the screwdriver. That will jump the starter solenoid. As a result, the electric current will pass between the ignition switch and the starter motor.
Make sure you have a friend in the car. Ask them to ignite the engine when you touch the contacts with the screwdriver. Step away from the vehicle as soon as you hear the roar of the engine. And just like that, you are ready to get back behind the wheel.
Bypass starting poses a risk to your health. Also, it is not a permanent solution. You will still need to go to the repair shop even if you get the engine going.
Keep in mind that this trick may not work on all automobiles. The starter motor of some cars cannot be accessed easily.
How Much Will It Cost to Replace a Faulty Starter Solenoid?
The cost of a starter solenoid repair or replacement will depend on the make of your car. In most cases, the price ranges from $100 to $150. To change the entire starter system, you may need around $450–$700.
More than half of the cost will go for labor charges rather than for parts. Also, most auto repair shops don’t do solenoid repairs. They prefer to replace the faulty solenoid with a new one.
That is why some car owners prefer to it themselves instead of seeking professional help. But this has many risks. So, avoid doing that unless you are an experienced layman mechanic. The starter solenoid may be a small car part, but you shouldn’t underestimate its power.
