How to Test a Starter Solenoid – The Ultimate Guide

Understanding how to test a starter solenoid will help you overcome the worry about the proper functioning of the component, especially when the vehicle fails to start.

A vehicle’s starter solenoid is a crucial component that plays a vital role in starting the engine and ensuring that it runs efficiently. The component is located within the vehicle’s engine compartment near the starter motor.

So, if your vehicle suddenly fails to start and you’re wondering what could be wrong, ensure to test the solenoid, among other components.

This article provides a step-by-step guide to take you through the process. You will find out whether the solenoid is the issue or not after reading this article.

How to Test a Solenoid Step by Step Guide

Firstly, you need a partner to assist you in testing your vehicle’s solenoid. The partner will help you engage the vehicle while you do the checking. Also, you need a multimeter, especially when carrying out a voltage test on the solenoid.

Note that you need to wear protective materials such as eyeglasses and hand gloves to avoid unexpected outcomes. Did I forget to say you also need a set of jumper cables? However, this is optional. Now, let’s get to work.

how to test a starter solenoid

Locate the starter solenoid

Locating your vehicle’s starter solenoid sometimes depends on the vehicle’s make and model. Some manufacturers’ brands have the component on a specific area within the engine compartment. However, this is a general approach to identifying the solenoid.

Firstly, open the vehicle’s hood to access the engine. The solenoid and the starter are both located within the engine compartment. The starter is the large cylinder that has another smaller cylinder on it.

The smaller cylinder has two terminals projected from the end. This is actually the solenoid. Once you find it, move to the next stage.

Perform the ‘click’ sound test

Remember where I stated that you need an assistant above? Now is the time to engage your assistant (probably a good friend). Ask your assistant to get in the car and start the engine. Meanwhile, you need to stay calm close to the solenoid to listen for a ‘click’ sound.

Ensure to stay a bit far from the engine while listening to the sound. Also, make sure that you wear your protective materials as you perform the solenoid test.

Now, let your assistant start the vehicle; then, listen carefully to get the sound. If the sound comes out loud and strong, it means the solenoid is working, and it has good power output.

On the other hand, if the sound is a little bit quiet or repetitive, the solenoid is most likely lacking enough power. Meanwhile, if you can’t hear any sound, you most likely have a defective solenoid.

This approach can also be useful for a golf cart because the symptoms of a bad solenoid on a golf cart are pretty similar to that of other vehicles.

Engage a multimeter test

In most cases, it is advisable to go further and carry out a multimeter test on the solenoid, even after hearing the loud click. This will help you ascertain the voltage level of the solenoid.

In order to perform this test, ensure you have a working multimeter. Then, connect the multimeter’s positive wire (red wire in most cases) to the solenoid’s positive terminal. This terminal is the one connecting to the starter.

After that, connect the multimeter’s negative terminal (black wire in most cases) to the terminal that projects from the vehicle’s battery.

Now, ask your assistant to start the engine while you maintain a distant position from the engine. Once your assistant turns the ignition on, the multimeter is expected to read a drop in the voltage level.

The range should be about 0.5V; therefore, if the voltage fails to drop or it reveals anything less or more than 0.5V, you most likely have a bad solenoid. Meanwhile, for those asking how to test solenoid without a multimeter, the first approach is recommended for you.

starter solenoid

How do you fix a solenoid?

If your vehicle’s solenoid is having an issue, attempting to fix it can restore it instead of running off to buy a new solenoid for replacement. So, follow this procedure to fix your vehicle’s solenoid.

Remove the starter

Firstly, get your vehicle to park properly by engaging the emergency brake or neutral. Then, open the hood and disconnect the battery’s negative terminal.

After that, get a floor jack to raise the vehicle and place two jack stands beneath the frame close to each wheel. Then, remove the starter by following the procedure on your car manufacturer’s manual.

Take out the main starter wire.

Get under the vehicle and take out the main starter wire, as well as two to three ignition wires at the back of the solenoid.

Remove the mounting bolts on the starter.

Next, remove the bolts that hold the starter in place with the correct socket. Then, pull off the starter by turning and twisting it until it is out of its mounting position. After that, place the starter motor in a vice and clamp the case gently.

Now, remove the wire connecting the solenoid to the starter. Ensure to use a good screwdriver to take off the solenoid’s backing plate.

Pull out the round plunger.

Locate the round plunger; it’s pretty small. Then, pull it out and keep the small ball and spring in a safe place. Also, note the way the ball and spring fit on the plunger so that you can fix it appropriately. Next, remove the studs that hold the copper and remove the old copper.

Install the new copper

Now place the new copper in place and fix the two stud bolts; then, tighten them properly. After that, get the ball and spring; then load them in place into the plunger. After that, push the plunger into the starter solenoid.

Replace the plates on the solenoid and reconnect everything

Get the plates back on the solenoid. If they had bolts on them, ensure to bolt them in place properly. After that, fix everything else in the reverse order that you removed them; from the starter wire to the ignition wire, etc.

Now, take off the jack. After that, you can start the vehicle as much as possible and ensure that the solenoid makes good contact.

How do you bypass a solenoid?

Knowing whether the fault is from your vehicle’s solenoid or starter is quite tricky when your car won’t start. So, in order to ascertain whether the solenoid is the issue, bypass the solenoid. The following procedure will help you to bypass your vehicle’s solenoid:

Locate the vehicle’s starter motor

The starter motor is located around the lower part of the engine on the driver’s side, about half of the engine. The starter motor is around 8 inches long with a tubular design. Also, the solenoid is attached to the starter motor by the side, having two wires at each end.

Identify the 2 metal contacts behind the solenoid.

Look at the back of the starter solenoid to locate the 2 metal contacts. One of the metal contacts has a starter wire that goes into the engine bay and connects to the vehicle’s ignition switch.

The other metal contact has a wire that connects to the starter motor, which is the generator or jumper wire.

Get an insulated screwdriver and place the blade across the metal contacts.

Get an insulated screwdriver with the metal blade placed across the metal contacts. It will help bypass the solenoid and create a connection between the ignition switch and the starter solenoid.

Ask someone to help you turn on the ignition.

At this point, ask a friend or anyone there to assist you in turning the vehicle’s ignition to start position with the key. Don’t expect the engine to start (remember, you’ve just bypassed the solenoid).

However, listen for a humming sound consistently coming from the vehicle’s starter motor. When you hear this, it means the bearings in the starter motor are okay, and the solenoid is bad.

On the other hand, if the starter motor produces a choppy sound or doesn’t start at all, it means that the starter is bad.


Why would a solenoid not work?

A solenoid may fail to work for several reasons, including inappropriate voltage, electric spike, contact with liquid, etc. The solenoid is responsible for converting electrical energy into useful mechanical work.

Since the solenoid deals with electricity, any slight changes in the voltage to an improper level will cause the coil to either burn out or fail. On the other hand, an unexpected spike or surge in electricity can also affect the coil and result in the solenoid’s inability to work.

Lastly, water can lead to several damages within a car, and the solenoid is not free from this reality. Water and other liquids have the tendency to damage the coil and cause it to fail. Endeavor to pay attention to symptoms of a bad solenoid in transmission to fix the issue quickly.

How do you check if a solenoid is working?

Checking whether a solenoid is working is pretty straightforward. So, if your car fails to start and you suspect that your vehicle’s solenoid isn’t working, do not hurry into concluding. First, test to check whether the issue is with the solenoid or another component in the vehicle.

Follow this procedure to check if your vehicle’s solenoid is working or not. Meanwhile, you need a multimeter, jumper cables, protective gloves, and eyewear to do the check perfectly. This information is also useful to those asking how to test a 4 port solenoid.

Firstly, locate the solenoid on the starter; you need to open the hood and locate the starter in the engine. The starter is a large cylinder that has a smaller cylinder on it (this is the solenoid). 

After identifying the solenoid, get a friend to start your car while you listen to a clicking sound from the solenoid. Ensure to maintain a distant position from the engine.

Once your friend starts the car, and you hear a loud clicking sound, it means the solenoid is working. You can also find out how to test solenoid with a battery as an alternative for the sake of experimenting.

What is the resistance of a solenoid?

Using a multimeter to check the resistance of a solenoid has a lot to say about the solenoid, whether it has an open circuit, a short circuit, or it is partially shorted.

The resistance of a solenoid under an ideal condition should be around 0-100 Ohms or thereabout. For example, a solenoid that reads resistance of about 10 Ohms at 20 degrees centigrade will have a 9.2 Ohms resistance at 0 degrees centigrade.

Meanwhile, a solenoid at 80 degrees centigrade will have a 12.4 Ohms resistance. It is vital to understand that having k-ohm range resistance is not good. Also, if the solenoid reads as low as 1-2 Ohms, you probably have a shorted circuit.

How do you jump a starter solenoid?

If your car fails to start and you suspect that the issue may be the starter solenoid, you may want to jump that component.

Understanding how to test a solenoid with a screwdriver will be helpful at this point. In order to jump a starter solenoid, simply get an insulated screwdriver with a metal blade.

After that, place the screwdriver’s metal blade against the 2 metal contacts (terminals) at the back of the solenoid. Then, ask a friend who’s available to help you turn the car’s ignition key to start position.

Once you do this, you will hear a humming sound from the starter motor, which reveals that it is okay, but the solenoid is faulty. On the other hand, you may hear a choppy sound which signifies that the fault is from the starter motor.

Are solenoids repairable?

Of course, a vehicle’s solenoid is repairable; hence, you don’t need a new replacement whenever you notice a malfunction of the component.

Some car owners are usually anxious whenever their car develops a fault. They are quick to conclude that a component needs a replacement.

However, while there are faults that may require the replacement of the faulty components, the solenoid may not require a replacement in most cases. A quick diagnosis and repair can restore the component back in shape to function properly.

What wires go to the starter solenoid?

A starter solenoid has three wires that connect to the three terminals of the component. The battery terminal known as the “B” terminal connects the starter solenoid to the battery’s positive cable.

Meanwhile, the start terminal known as the “S” terminal receives the power output from the vehicle’s ignition switch. Lastly, the motor terminal known as the “M” terminal is the one that is attached to the cable which connects to the vehicle’s starter motor.

When you turn your car’s ignition key to start the car, it sends voltage to the “S” terminal. Then, the voltage automatically energizes the electromagnetic windings of the solenoid, which pulls the plunger of the starter, making it push a disc to a set of contacts.

The contacts are attached to the “M” and “B” terminals. Current travels from the battery to the car’s starter motor, which cranks the engine to start once the contact establishes a connection.

How much does it cost to fix a solenoid?

The estimated cost of fixing a solenoid depends on the vehicle’s make and model. While some may be relatively cheap, others may be quite expensive, as the case may be. Typically, the cost of fixing a single solenoid ranges between $200 and $500.

On the other hand, if you are replacing an entire solenoid pack, it will cost around $250 to $700. The total cost covers the parts and labor fee, respectively.

So, your total budget will depend on whether you’re fixing a single solenoid or a pack. However, ensure to find out how to test a solenoid coil and other parts of the solenoid before buying an entire pack.

Final Words

This article has just unveiled the step-by-step guide on how to test a solenoid. So, if you’re experiencing difficulty starting your car, ensure to engage the information provided in this article to verify if the issue is the solenoid.

However, the process will be pretty much easier for DIY enthusiasts than the average car owner, who may not know much about automobiles. So, if you’re not a DIYer, kindly contact an expert auto mechanic to help you with the test.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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