Knowing the symptoms of a bad starter relay will save you from being stranded in the middle of nowhere. The starter relay is one of the essential and most overlooked components of the ignition system.
This critical ignition component is designed to direct current from the car battery to the starter solenoid, triggering the starter motor to turn the engine. This means it serves as a switch between the starter motor and the starter solenoid in a vehicle.
Starter relay issues are not common. It rarely fails, but when it does, it might keep you stranded because your car won’t start. However, several factors can cause a starter relay to fail.
They include lousy circuits, corroded circuits, bridged contacts, wet relays, or even over-aged relays. When your starter relay fails or starts going bad, you’ll notice some warning signs to alert you to fix it on time.
This article will discuss these signs at length and examine how to tell if the starter relay is bad. We’ll also discuss the functions, what causes them to fail, and how to fix or replace them.
What Is A Starter Relay?
A starter relay is an electrical component that controls the starter motor and solenoid circuit in your vehicle. It is a high-current switch that supplies electricity to your car’s starting motor. It is normally controlled by the ignition switch circuit.
When you turn the ignition key, a little quantity of electricity is transmitted from the battery to the starting relay.
This triggers the relay, allowing significantly more electricity to travel from the battery to the starting motor. The motor then turns on the engine, and your vehicle begins to move.
In your starting circuit, a completely working starter relay is a crucial safety element. The car will not start if the starting relay, the starter motor or any other electrical system component fails.
Types of Relays
- Electromechanical Relays: Use a physical mechanism to open and close contacts, making them reliable for many traditional applications.
- Solid-State Relays: Utilize semiconductor devices to switch the circuit, offering faster switching times and longer life spans due to the absence of moving parts.
- Hybrid Relays: Combine the benefits of both electromechanical and solid-state relays, providing a balance of durability and performance.
The choice of relay depends on factors such as the required switching speed, load capacity, and environmental conditions.
What does a starter relay do?
A starter relay is an ignition system component specially designed to transmit power from the car battery to the starter solenoid. This implies it is a switch between the starter solenoid and the starter motor.
It is solely designed to transmit current from the car battery to the starter properly. Most car owners and mechanics confuse starter relays with starter solenoids. These are two different ignition system components.
The starter solenoid works as an actuating coil of a connector, which carries electrical current from the starter solenoid to the starter motor. Starter solenoids are designed to engage the starter pinion with the ring gear of an engine.
So, how do the starter relay, starter solenoid, and starter motor work together? When you insert your key into the ignition key to turn it on, it energies the starter relay, which transfers power to the starter solenoid, which transmits power to the starter motor.
A starter relay sends small electric power to the starter solenoid when you turn on the ignition key, while the solenoid draws a large current directly from the car batteries.
This causes the solenoid to transfer power to the starter motor, which in turn spins the flywheel.
All modern starters follow this process. They rely on the starter relay to send power to the solenoid, engaging the starter to turn the flywheel. The starter relay plays a significant role in starting your car.
Starter Relay Location
The starter relay is most often located under the car hood, found in the power distribution center. It can also be located in the fuse block in the cabin.
The relay has wires coming in and out of it. However, there are many other relays used in the car that look similar. If you are unsure which one is the starter relay, reference your service manual.
Symptoms of a bad starter relay
Like every other mechanical and electrical component in your vehicle, the starter relay displays some signs that show it’s failing before it finally stops.
Some of these signs are the same as the symptoms of a bad starter solenoid, and some indicate a bad starter motor. This makes it difficult to find. Let’s look at these symptoms below.
#1. The car won’t start.
The most common sign of a faulty or failing starter relay is that your car won’t start when you try to start it. If you try starting your car and there’s no sign of starting or even a click, and your interior lights are bright, it may be an indication of a bad starter relay.
The problem might be that your car starter relay fuse is blown. Regardless of how many times you try, the car will not start. However, if you hear a clicking sound when trying to start the vehicle, it could mean your starter relay has not gone completely bad.
In either case, you have to diagnose your ignition system if you know your way around it. If not, contact a professional mechanic for a thorough check.
#2. Starter relay that stays on even after the engine has started.
When you turn on your ignition switch, it sends an electrical current to the starter relay, which transfers the current to the starter solenoid. The solenoid sends the power to the starter motor, which rotates the flexplate to start the engine.
Turning off the ignition switch should work the opposite; both the starter solenoid and the motor should stop working.
If it doesn’t work in this sequence and the relay stays on even after the engine has started, you have a bad or failing starter relay. It could be the relay is sending a steady current.
This usually occurs when the relay is touching somewhere or exposed to high electrical power. You need to diagnose and fix this problem immediately because it could damage the entire starter system.
#3. A series of rapid clicks from the starter.
The starter relay clicks, but no crank shows the starter motor is not receiving enough electrical current from the relay to turn the engine.
This is also a sign of a low or dead battery. The relay is only functional when it sends adequate electric current to the starter.
Lessor high power could either damage the entire starter system or won’t start the vehicle, accompanied by an annoying clicking sound.
Both could be a result of a corroded or aged relay whose contact points are deteriorated. Repair only requires cleaning the contact points to ensure proper flow or changing an old relay.
You can clean a corroded relay by scrapping the rusted surface with sandpaper or sand scraper. You may consider replacing the relay for better output.
#4. Intermittent issues starting the car.
There are times when the engine won’t start unless you switch the ignition key on and off a couple of times.
It is a sign of a bad starter relay, and it’s caused mainly by corrosion, dirt, debris, or extended exposure to heat. The corrosion and residue will reduce the flow of electrical current within the circuit.
A starter relay is a simplified ignition system component that doesn’t contain many parts, and that’s why it rarely fails. But when it does, it has to do with electrical conductivity problems.
Causes of a bad car starter
Understanding what causes starter issues can help you prevent them in the future. Here are some common causes of starter problems:
#1. Wear and tear.
Like any mechanical component, starters wear out over time. The starter gear, bushings, and electrical components inside the starter can degrade, leading to performance issues.
#2. Electrical problems.
Faulty wiring or connections in your car’s electrical system can cause a starter to fail. Corrosion, loose connections, or damaged wires can disrupt the flow of electricity necessary for the starter to function.
#3. Starter relay issues.
A properly working starter relay is an essential part of your starter system. It sits between your starter motor and the car battery. If your relay isn’t working, your starter motor won’t be getting any electrical power, so it simply won’t work.
#4. Faulty solenoid.
The solenoid is crucial for engaging the starter motor. If it’s failing, the starter won’t turn the engine over. This can be due to electrical current issues or the solenoid’s magnetic field.
#5. Battery issues.
While the starter itself is not a problem, a weak or dead battery can prevent it from functioning properly. Make sure your battery is in good condition and fully charged.
How To Test a Relay ?
To diagnose the car’s failure to start caused by a malfunctioning relay, you need to ensure that a faulty relay is the root cause. To confirm the relay is functioning properly, the starter relay needs to be tested. There are different ways to test a relay.
- Swap Relay: Swapping the relay is one of the most popular and easiest ways to test it. Simply replace the suspect relay with another relay of the same rating. If this resolves the issue, then there was indeed a problem with the relay.
- Relay test with Multimeter: Testing a relay with a multimeter is a common method to diagnose relay issues. One common problem with relays is a burned-out coil. To check the relay coil, use a multimeter.
- Relay Bench Test: This test involves removing the relay from the vehicle and manually applying power to its terminals to see if it functions as expected. It’s a more thorough test than simply swapping relays and can help identify if the relay itself is the problem or if there are issues elsewhere in the circuit.
Diagnosing a Bad Starter Relay
You can diagnose a bad starter relay through several steps. Here are some practical ways to identify the issue:
- Voltage Testing: Use a multimeter to check the voltage going to and from the relay. Proper voltage indicates a functioning relay.
- Inspect Wiring: Look for loose, corroded, or damaged wiring connections.
- Listen for Sounds: Pay attention to any clicking sounds when turning the ignition key.
How to fix bad starter relay problems
If the relay fails due to corrosion or dirt on the leads, cleaning the connectors will restore the relay. You might need to inspect and clean the internal construction of the relay box.
Depending on how dirty or corroded the connectors are, you may only need to clean the external parts. Cleaning the dirt and grime requires a wire brush and baking powder. You may also need a blower and a microfiber towel for the cleaning process.
Regardless of the cause, the best option for fixing a starter relay problem is to replace the relay. Replacing the relay means solving the problem once and for all.
The starter relay is a long-lasting component that can last up to 100,000 miles. So replacing it is worth the cost. Let’s explore the processes involved.
#1. Replacing a bad starting relay.
Starter relay replacement is a pretty easy and quick fix. There are several processes to follow when installing a new starter relay. It all depends on the type of relay you’re replacing.
remove a starter relay
Fuse box starter relay
- Step 1: Raise the hood and disconnect the negative battery terminal with a sizeable wrench.
- Step 2: Find the fuse box. It is usually a black lid box located near the battery. If you’re finding it difficult to identify it, consult your owner’s booklet. The booklet will help you locate the starter relay.
- Step 3: Disconnect the relay.
Fender wall relay
This starter relay is directly mounted on the firewall or fender. Follow the below steps to remove it.
- Step 1: Disconnect the battery terminal using a sizable wrench.
- Step 2: Disconnect the leads that go to the relay terminals. Use a matchable wrench or socket to loosen nuts that hold the relay leads.
- Step 3: Take off the mounting screws that hold the relay to the fender.
#2. Installing a starter relay.
Installing a fuse box starter relay is one of the most straightforward DIY jobs. There are no bolts, screws, or nuts too tight – and nothing to worry about.
Compare both new and old relays. Once you’re sure they’re the same, take the new relay and match the pins on their slots in the fuse box.
Gently push it down until it gets to the end of the slot and seats evenly. Cover the fuse box and reconnect the battery terminals.
Follow the below steps to mount a fender wall relay;
- Place and hold the relay against the installation point.
- Plugin the screws and tighten them to hold the relay.
- Connect the starter circuit leads to the battery terminals.
- Ensure you connect the right wire to the right post.
After installation, give yourself proof of doubt and recheck the work. Ensure the cables and connectors are intact on the fender wall relay.
Test the starting system. If everything works, pat yourself on the back. However, if you’re not the DIY type and not comfortable with this guide, do not hesitate to seek professional assistance.
Potential Risks and Downsides
While bypassing the starter relay can start the car, there are significant drawbacks:
- Increased Wear and Tear: Direct connection methods may cause excessive wear to the starter motor and other components.
- Safety Risks: Bypassing the relay incorrectly can lead to electrical shorts or fires.
- Damage to the Vehicle’s Electrical System: Improper handling might damage other parts of the vehicle’s electrical system, leading to costly repairs.
How to Prevent Starter Failure
Proper maintenance can help prevent premature failure and keep your engine starting reliably.
- Start by checking the electrical connections regularly. Loose or corroded wires can interrupt the flow of power to the starter, leading to weak starts or failure to start altogether. Make sure the connections are tight and clean from rust or debris.
- Ensure that your battery is healthy, as a weak or dying battery forces the starter to work harder, which can cause unnecessary wear. Regularly test the battery’s voltage and replace it as needed.
- Monitor for oil leaks around the engine and transmission. Leaking oil can drip onto the starter, causing internal damage and potentially shorting out the electrical components. Address any leaks promptly to protect the starter and other nearby components.
- Listen for any unusual sounds, such as grinding or clicking when starting the engine, as these can indicate early starter issues.
How Much Does It Cost to Replace a Starter Relay?
Replacing a starter relay involves both parts and labor. The total cost can vary widely depending on the make and model of your vehicle, as well as where you get the replacement done.
#1. Parts Cost.
The price of a starter relay alone can range widely based on the vehicle type and the quality of the part. Here’s a general breakdown:
| Vehicle Type | Starter Relay Cost |
|---|---|
| Economy Cars | $15 – $40 |
| Mid-Range Vehicles | $30 – $60 |
| Luxury or Performance Cars | $50 – $100 |
#2. Labor Costs.
Labor costs for replacing a starter relay also vary depending on the service provider and your geographic location. Here’s what you can expect:
- Independent Mechanics: Typically charge between $50 to $100 for labor.
- Dealerships: Costs may be higher, ranging from $80 to $150 for labor.
#3. Total Replacement Cost.
Considering both parts and labor, here’s an estimate of the total cost for different vehicle types:
| Vehicle Type | Total Replacement Cost |
|---|---|
| Economy Cars | $65 – $140 |
| Mid-Range Vehicles | $80 – $160 |
| Luxury or Performance Cars | $130 – $250 |
#4. DIY Replacement.
If you’re comfortable working on your vehicle and have basic mechanical skills, you can save on labor costs by replacing the starter relay yourself. Here’s what you’ll need:
- Starter Relay: Purchase the appropriate relay based on your vehicle’s specifications.
- Tools: Basic hand tools like screwdrivers, wrenches, and possibly a multimeter for testing circuits.
Installing the relay yourself would bring the cost down to just the price of the part, which can be significantly less than paying for both parts and labor.
FAQs.
Q: Does a relay click when it’s bad?
If you have a failing or bad starter relay, it will not provide adequate electrical current to power the starter motor.
As a result, regardless of how many times you revolve the engine, it’ll not start. A defective starter relay will produce a click sound when you turn on the ignition.
Q: How do you check if a starter relay is working?
The only tool required to check a starter relay is a multimeter. Get a multimeter and set it on an ohms scale. Place one of the probes on the ground cable and the other probe on the ignition circuit terminal.
A good relay should be under 5 ohms. If the readings go above 5 ohms, it shows you have a bad starter relay that needs replacement.
Q: Can you jump-start a car with a bad starter relay?
The answer is no; you cannot jump-start a car with a bad starter relay. In order to jump-start a car, the starter relay must be in good working condition.
If the starter relay is not working properly, it will not provide the necessary power to the starter motor, and the car will not start.
Jump-start will only boost the battery power long enough to start the engine; it will not fix a bad starter relay. If you have a bad starter relay, you will need to replace it with a new one.
Q: How do you bypass a starter relay?
You can bypass a starter relay by bridging the power input and power output pins to the relay. But to know this, you need to use a wiring diagram and a multimeter to make sure you’re doing it right.
Q: Are a starter relay and a starter solenoid the same thing?
No. The starter solenoid is located on the starter motor, and a starter relay is in most cases located in the fuse box in the engine compartment. They serve two different purposes.
Final Words
It is critical to ensure that the starter relay is functioning properly. Consider it as part of your car’s regular maintenance practices. Hence, knowing the symptoms of a bad starter relay and how to fix it will save you from getting stranded in the middle of nowhere.
I believe this article has guided you on the information and processes you need to fix your starter relay problems. You now know the functions, causes, and signs of a starter relay. You can diagnose, fix, or replace a bad starter relay.