Starter Relay – How To Diagnose A Bad Relay?

Starter Relay – How To Diagnose A Bad Relay?

Are you having some starting issues? Do you keep getting that click-click sound from the car whenever you try to start the engine? Well, in this case, you might be experiencing a problem with the starter relay. But you shouldn’t worry because there will be a lot to cover.

Having a problem like this can be a really frustrating thing to deal with. Why I’m saying this? Well, it is really simple. Imagine that you try to start the car in order to go to work. The car doesn’t want to start and you end up being at home or late for work. Not an ideal situation because your boss could be furious at you.

This is why you need to learn all of the possibilities out there that are and could cause you to lose your ability to start the car. A lot of people will instantly think that the battery must be the problem, but this isn’t always the case. There are a ton of other components that are in charge of starting like this relay, the solenoid, the starter motor. All these units work together to deliver good starting ability. But how to know when a relay is bad? Well, that’s why we are here.

First, we are going to cover what is a starter relay. Then we will take a look at the location as well as the diagram. Later on, we will discuss the symptoms and how to diagnose a bad relay, and at what cost. Lastly, we will answer some common questions. So, if you want to learn more, follow along.

What Is A Starter Solenoid Relay?

Now before we learn more about the location of this starter solenoid relay. Let’s first take a look at the basics when it comes to this component. We need to understand what it does and what type of role does it play. If you feel like you have the grasp of knowledge when it comes to this component you can move on to the symptoms. If not keep up with us for a bit.

A starter solenoid relay is simply an electrical component that acts as a switch. This switch basically completes the electric circuit when activates and makes starting your vehicle possible. Without this switch, you will not be able to start your car.

So, if you cannot start the car and someone is pulling tricks on you, you should check if you have this relay on your car. But where you can find it we will discuss it later on in the article.

What is important for you is to know the method of action of this component. This component works remotely. Meaning that whenever the switch senses a need to turn on, it turns opens up the circuit. So, the power from the car battery could travel to the starter solenoid.

When the power from the starter solenoid gets there, it automatically travels to the starter motor and turns over the motor to start the car. Since the solenoid and the motor are basically one unit. The solenoid usually sits right on top of the starter motor and a lot of people are confusing these things. And you shouldn’t.

Remember, the starter solenoid relay is first, then there comes the solenoid and the motor. This is the method of action. But where the starter relay is located? Let’s find out.

Starter Relay Fuse Location

Now as we cleared the basics when it comes to this relay. Let’s now focus on the main location of this component in other words, how you can find it on your vehicle, what is the starter relay fuse location?

The location of this component really depends on the make and model. In older cars, these components are often mounted onto the firewall or on the fender wall. These components usually are cylindrical and do not resemble the modern types when it comes to the visual aspect.

This is why when you are dealing with an older vehicle, you should consult your owner’s manual for more data on the location of this component.

In more modern cars, this component is usually mounted inside of the fusebox. The fusebox is simply a big box that is often found inside of the engine bay or next to the driver’s pedals. This fusebox contains all of the important fuses and relays that you need so your car would work properly without any issues.

For more info on the starter relay fuse location-specific for your car, you can consult online and look for your specific make and model or browse some forums specific to your car. There is a ton of useful data out there.

These relay components are usually resembling black square boxes that are attached to the fusebox next to the fuses. There are a few of them and telling which is which can be rather difficult.

For this, you should look at the fusebox cover. Usually, there is important information that tells you about the purpose of the fuses and relays inside of the fusebox. Then find the one relay that you need.

Starter Relay Fuse

Now let’s clear something out. A lot of people think that this is a starter relay fuse. Which actually is not, a relay is not a fuse.

Fuses have a different purpose and that is to prevent some electrical problems when the electrical circuit shorts out. When there is too big of a voltage because a component is faulty, the fuse will pop in order to prevent your car from catching fire.

If there were no fuses, driving a car would be a lot more dangerous than it should be. These fuses are basically lifesavers. It’s much simpler to replace a fuse than to replace a whole car.

A relay on the other hand is a completely different beast. These devices are there to complete the circuit. Meaning that they get the information they need and are completing the circuit and your car is able to start.

If the relay is broken, your car will not be able to start and will have problems. In this situation, you will think that you have other problems with your vehicle and something else has broken.

But in reality, a simple relay could be the one that is causing all this headache to you as an owner. That’s why never think that a starter relay fuse is a fuse. It’s a switch that completes an electrical circuit and that is its job. Now let’s move to something else.

Starter Relay Wiring Diagram

Now before we dive into the symptoms of a bad starter switch (which could be verified by understanding how to tell if starter is bad, and get your car going again by figuring out how to jump a starter). Let’s take a look at the starter relay wiring diagram. How does everything works together as a whole unit and makes your car to be able to start? Let’s explain.

Everything starts with the ignition switch, you put the key inside of the switch and then you crank the car. All the magic happens from this ignition switch.

There are two signals from this switch that travel to different components. One to the starter relay, and the other to the fuse. The signal from the fuse travels to the positive battery terminal while the signal from the starter relay travels to the starter motor solenoid.

Then this relay says ”hey the conditions are met, let’s open the circuit”. Once the circuit is open, the power from the battery travels to the starter solenoid. And then from the solenoid, the electricity travels to the starter motor and makes the car start. Simple as that.

It might be a bit confusing at first. But use the research skills that you have and try to go online and browse some images of a starter relay wiring diagram. This is how you will be able to tell how everything works together.

The important thing for you is to understand what all these components do and make sure that they are in working condition.

Unless you want to become a car electrician and want to know how to learn and measure current, resistance, and other values. For this, you will need a multimeter tool. Later on, in the article, we are going to discuss these things more in-depth. Now let’s focus on the bad starter relay symptoms.

Bad Starter Relay Symptoms

Now as we cleared all about this component and we learned what it really does and in what ways it works. Now let’s focus on something else.

And that are the bad starter relay symptoms. What type of symptoms you could face whenever there is a problem with this component? As you probably know, whenever a component fails, there will be some kind of symptom that is produced.

And based on these symptoms, you should make your call and determine what could be the problem. So, if you want to learn how to diagnose the problem, follow along.

1. Vehicle Does Not Want To Start

The first in our list of bad starter relay symptoms that we are going to cover is the situation when the vehicle doesn’t want to start at all. And this is the most common situation that you will face whenever you face a problem like this.

The car simply will be irresponsive and will not react whenever you try to crank it. Nothing will happen. In most cases, not even a clicking noise will occur.

Starter Relay

This is the case because this relay is really important and controls basically everything when it comes to the ability to start the vehicle. If this is the situation you are into, then you either have a problem with this component, a problem with the solenoid, or a completely dead battery.

If the battery is dead, then you will not have power to the accessories. So, this is a simple way to check a battery. If the accessories work then your battery is probably in good condition. Other components like the relay and the starter motor and the solenoid need to be checked separately with a multimeter.

2. Vehicle Sometimes Start Sometimes Don’t

The second in our list of bad starter relay symptoms that we would like to cover is the situation when the car sometimes starts and sometimes nothing happens, not even a single click.

This is a clear sign that this relay is working intermittently. Sometimes It works and sometimes it doesn’t. This could be due to many things.

But the most common ones are that the component is near the end of its lifespan and will soon fail completely. Or there is debris or rust that accumulated on the connections of this unit.

It is worth checking the connections and determining if there is a problem with the connections. If there is some rust accumulated, then cleaning the connections is the way to go. Or replace the component with a completely new unit to avoid any future headaches. Now let’s move on to the next symptom.

3. Clicking Sound From The Starter

Another common symptom in our list of bad starter relay symptoms is the clicking noises that are often the case.

These clicking noises can be due to a weak or a dead battery or a bad solenoid. But sometimes this relay can also cause these clicking noises.

This happens in the case whenever the component is damaged and doesn’t always stay up to the task of doing its operation in the way it should be. So, when you hear a click-click sound whenever you try to start your vehicle. This is one of the options.

It happens rarely, but this component can also cause this clicking sound. Later on, we are going to explain how you can diagnose the matter and determine if this is the component that is causing all of these headaches to you. Now let’s move on to the last symptom.

4. Relay Stuck In Closed Position

And the last in our list of bad starter relay symptoms that we are going to cover is the situation when this component is stuck in a closed position.

Yes, that’s right, the relay can get stuck in a closed position and whenever this happens there are a ton of electrical issues around.

This component should get in the off position once the car’s engine started. But if this component is in the on position all the time, it could lead to some catastrophic event.

More precisely, this current that will go to the starter motor could damage the starter and the solenoid in the process. This could be a really expensive endeavor for a simple component like this relay.

So, whenever you notice that something is going on and the starter motor is working and strange noises come from the engine bay. It means that you need to address the issue sooner and avoid any further damage to these components and pay a ton of money in order to sort them out.

This is why you need to diagnose the problem. And that’s what we are going to cover up next.

How To Diagnose & Replace A Bad Starter Relay?

Now as we covered the bad starter relay symptoms, let’s now focus on something else. Namely, the diagnostic process as well as the replacement of this important relay.

The first thing you need to do is to learn if this is a relay-related issue. So, if the accessories inside of the car are working perfectly well and you have trouble only with starting the engine, then this for sure is a problem with either the solenoid or the relay.

If the solenoid is the one that is bad then you will highly likely get a clicking noise. If the relay is bad then there will be absolutely nothing in 99% of the cases. So, in this case, you might be wanting to check the fuse box and locate the relay based on the information on the cover.

Once located the relay, just remove it from its position and now you can test if the relay is working or not. You can do this with a multimeter tool and a small battery. You just need to check if there is resistance whenever there is power to the relay.

If there is, then the circuit is closed. If there is no resistance, the circuit is open and the relay is not performing as it should. For a visual way of how you can learn this process, you can watch the video that we attached.

If you determine that the relay is the problem, then you will only have to get a new one from your local parts store. Just make sure that you get the exact relay for your application. Not all relays are the same. Beware of this fact. But what is the cost to replace a relay? Let’s find out next.

Cost To Replace A Relay

Now as we covered quite a lot when it comes to this relay. Let’s learn more about the cost of this component. How much can you expect to pay in order to get it fixed?

If you do this at a shop, you will probably have to pay a few hundred dollars. Between $200 and $300 to be more exact. They will take your car and perform some tests on it. And this costs time and money. So, you can expect to pay something in this range.

What you can do is if you are somewhat sure that this is the problem with your vehicle. You can just get one from the local hardware store and replace it. You will highly likely find one for less than $10. So, it is much better to spend $10 and avoid spending $200 or more in some instances for a simple thing like a relay.

Bypass Starter Relay

You can use a trick to bypass this relay as well if you want to do so. This will be perfect if you want to start the car and go to the shop to purchase a new relay and replace it.

The process of this bypassing is really simple and you can check it out in the video. You only need a single wire to bypass the starter relay. Just make sure that your car is in neutral gear or park when trying to pull this off.


In this article, we have covered quite a bit when it comes to the starter relay. We first learned what this relay is and why it is so important. Without it, you will basically not be able to start the vehicle. It is that crucial.

Then we covered the symptoms of a bad relay and learned what can you expect when you have a bad relay. And the answer is that the engine will not like to start.

Then we learned how you can diagnose the problem and replace this component. As well as how you can bypass this component as well.


Now let’s answer some common questions concerning this component.

How Does A Starter Relay Work

This component works really simple, it basically creates a closed circuit and this closed circuit then allows electric current to be sent to the solenoid and starter to start the engine of the vehicle. It is there in order to protect the solenoid and starter from possible failures.

Where Is The Starter Relay

The starter relay is usually mounted close to the other fuses. The most obvious place for this is under the hood. There is a big plastic cover that protects the fuses. Remove it and you will have contact with the component. If it’s not there, you can check above the driver’s pedal controls. Here usually are some of the fuses. They sit behind a cover as well.

How To Tell If Starter Relay Is Bad

You can do this based on the symptoms and also by bench testing the component. If the car has power but doesn’t want to crank and doesn’t produce any signal. Then this component could be the cause. In order to be sure, you need to bench test the component with a multimeter.

How To Test Starter Relay

You can do this by getting yourself a battery that can deliver 12V and a multimeter. You need to power up the relay and then test the component and determine if it has resistance. If it does, then the component is good. If it doesn’t then the component has to be replaced.

How To Bypass Starter Relay

Bypassing this component is really easy. Just remove the plastic cover and remove the relay. Then get a wire and connect both connectors. Then the car will start. Just make sure that your car is in neutral when you do this practice.

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