Knowing the Symptoms of a Bad Starter Relay will save you from getting stranded in the middle of nowhere. The starter relay is among those very important but often forgotten parts of the ignition system.
The starter relay is that critical part of the ignition system, designed to send current from the car battery directly to the starter solenoid to cause the latter to have the start motor crank the car engine. In effect, it’s like a switch between the starter motor and the starter solenoid of your car.
Starter relay problems are rare; they hardly go bad, but in the event they do, they’ll likely leave you stranded since your car will not start.
Several factors can cause a starter relay to fail. They are; bad Circuits, Corroded circuit, Bridged contacts, Wet relay, Over-aged relay etc.
When your starter relay fails or is going bad, you’ll notice a few signs to make you fix it on time.
This article will discuss all of them extensively and how to tell if the starter relay is bad, beneath, we’ll also talk about what they do, what makes them fail, and how to fix or replace it.
What does a starter relay do?
A starter relay is a part of the ignition system which operates to transfer power coming from the car battery and activate the starter solenoid. In other words, it functions as a switch with respect to the starter solenoid and the starter motor.
The starter relay is not designed to do anything else except transmit current from the car battery to the starter properly. Because it does only one job and is so important, many car owners as well as repair mechanics get the starter relay and the starter solenoid confused. They are not the same but are two separate components of the ignition system.
How does the starter solenoid operate? A starter solenoid is the actuating coil of a connector “proper,” a conductor leading from the solenoid to the starter motor itself. Start solenoids are designed to engage a small pinion in the starter with a ring gear on the engine flywheel.
How do the starter relay, the starter solenoid and the starter motor work? An electrical circuit is energized when a person inserts a key in the ignition switch and turns it on. The ignition switch in turn energizes the starter relay, which transfers power to the starter solenoid, which transmits power to the starter motor.
The starter relay sends a small amount of electrical power to the starter solenoid and at the same time the solenoid itself draws a heavy current through the wire from the car batteries directly.
The result is that of a transfer of power in turn to the starter motor. This makes the starter engage with a pinion which spins the flywheel.
This is the general procedure which all modern starters follow. They depend on the starter relay to transfer power to the solenoid, evidence of starting an automobile. The relay does an important job for the car in starting it.
Symptoms of a bad starter relay
Like every other mechanical and electrical part in your vehicle, the starter relay gives some symptoms that show it’s failing before it finally packs up completely.
Some of these symptoms are the same as a bad starter solenoid, and some indicate a bad starter motor. This makes it tricky to find. Let’s check out these symptoms.
#1. The car won’t start
The usual symptom of a faulty or failing starter relay is that your car won’t start when you attempt to crank the engine. You turn the key, and there’s no sign of life or click, and your interior lights are bright, this could indicate a bad starter relay.
Another explanation may be that your car starter relay fuse is blown. Try as you might, the car will not start. But if you do hear a click when trying to start the vehicle, it may mean that your starter relay has not completely gone bad.
In either case, you must diagnose your ignition system if you are familiar with it. If not, see a professional mechanic for an in-depth check.
#2. Starter relay that stays on even after the engine has started.
Turning the ignition switch on sends an electric current to the starter relay which transfers it to the starter solenoid. The solenoid sends the power to the starter motor that rotates the flex plate to start the engine.
Turning the ignition switch off should work the other way around; the starter solenoid and motor should stop working.
If it doesn’t work in that order and the relay still stays on even when the engine is running, you have a bad or failing starter relay. It could be that the relay is putting out a steady current.
This usually happens when the relay is touching somewhere or exposed to high electric power. You need to diagnose and fix this problem immediately because it’s capable of damaging the whole starter.
#3. A series of rapid clicks from the starter.
The starter relay is clicking but no crank occurs. Looks like the starter motor doesn’t have enough current in it from the relay to turn the engine.
This is also a sign of a low battery or a dead battery. The relay doesn’t do much when sending a lesser high power to the starter. Lessor high power could either damage the whole starter system, or won’t start the vehicle accompanied by a most annoying click!
Both could be a result of an old relay whose contact points are already badly corroded. Repair is simply a question of cleaning the contact points to assure proper flow or changing an old relay.
Clean a corroded relay by scraping with sandpaper or sand scrapper. You may elect to change the relay for better output.
#4. Intermittent issues starting the car.
Sometimes the engine won’t start unless you turn the ignition key on and off a couple of times for it to switch on.
It’s indicative of a faulty starter relay, usually due to grime buildup, dirt, chaff or prolonged exposure to a heat source. The materials accumulate and prevent the current from making its way through the circuit.
Because a starter relay is simply an elementary component of the ignition system and doesn’t really possess that many parts it will rarely fail, but when it does it will always be due to electrical supply problems.
How do you troubleshoot a start relay?
Symptoms could arise from a faulty alternator or a dead or dying battery that needs to be changed or replaced. But to discover the real price of the trouble, you have to do a few tests Starter relay circuitry.
Do not panic! You can do the test. The following few paragraphs will explain how to Test a starter relay. We’ll simplify this job for you.
Since Diagnosing a starter relay is so easy because of its location. All you need is proper tools and of course knowledge.
Needed materials:
- Screwdrivers
- Test lights
- A piece of wire to act as a jumper
- Wrenches and socket sets (in case you need to lose anything).
#1. Testing the starter relay.
Before commencing the test, procure a fully-charged battery and a portable jumper cable. Alternatively, test your car battery ensuring it’s fully charged and not the source of the problem.
Be very careful throughout the testing procedure and careful where you place the jumper cables on the battery terminals.
#2. The testing procedures.
Locate the starter relay fuse. The fuse location varies from vehicle to vehicle. The fuses are generally located near the battery, sitting close to where the positive battery terminal is connected to it. Have an assistant help turn the ignition key to the ON position.
If you hear a click sound that’s weak, you will have to carry out an electrical resistance test, but if you hear a click, you must diagnose the starter relay for voltage drop.
#3. Diagnosing for electrical resistance.
- Grab a test light (or a multimeter, the latter preferred) and set it on the ohms scale. Touch one of the probes onto the earth lead and the other on the ignition circuit terminal. An okay starter relay should read below 5 ohms, while a higher rating shows it’s time to purchase another one.
- The second method of finding where resistance lies is to contact the red multimeter probe to the ignition circuit wire and the other probe to the earth wire. If it reads less than 12V when you turn on the ignition switch, it indicates a bad relay.
- Third in that short list comes one using a portable jumper cable. Contact the battery lead and the ignition circuit lead. A loud click means all is well. A single or a couple faintly heard clicks show a bad relay needing replacement.
#4. Diagnosing for voltage drop.
- Reset your multimeter to be on 20V DC
- Put the red probe of the multimeter on the red terminal lead from the battery. The black and thin wire put it on the lead that goes to the ignition circuit lead switch.
- Ask your assistant to turn ‘ON’ the ignition key, while you look at the reading on the multimeter. Don’t allow it to be above 0.2V. But above 0.2V, you have either a bad starter relay or a problem with the electrical conductivity of the starter relay that needs proper attention. You have to check the connectors and clean them.
What causes a relay to fail?
There are several things that could fail in the relay in your car. Here are some of them;
#1. Corrosion.
Corroded leads or connectors cannot transfer enough current. It will leave you with an intermittent starting issue, a buzzing or clicking coming from the relay and if things really get bad, your car will be idle and not start.
#2. Dirt and debris.
This part is usually sheltered from dirt, grime, and debris or dust being placed under the hood or dashboard.
With time, debris and dirt will form and impact the flow of the relay. As the dirt kickers worsen, it will keep sufficient amount of current from flowing and you’ll hear a series of buzzing or clicking sounds from the relay.
#3. Bad connectors.
Defective connectors is another cause of a failed relay. If current isn’t passing through the required amount, the relay is not going to work correctly.
You may hear some warning signals that something’s wrong by giving weak series of clicking signals. Aside from that, your car may not start.
#4. Too much heat.
A lot of heat is generated when high voltage is passing through when the relay is engaged.
The heat may burn or melt contacts causing them to stick together, closing the starter. Even when you haven’t turned on the ignition. That’s a crucial situation to pay attention to since it’s possible to damage the entire starting system.
#5. Overly aged relay.
Starter relay problems may not have much of a problem to find. You’ll discover it is an old relay that has diligently served you in hundreds of miles.
An aged part has that awkward tendency of having a part inside becoming unusable. In that case, it’s much easier replacing it. Nothing more. Now you know of the problems and symptoms of a bad starter relay, how do you fix it? The answer is largely based on how the failure occurred.
If it’s due to dirt or debris, then cleaning them will solve the problem. And if it’s due to excess heat or faulty connectors, consider replacing them. That brings us to how to repair faulty starter relay problems.
How to fix bad starter relay problems?
In the event the relay goes bad and the corrosion or dirty connectors are a possible cause, cleaning the connectors will restore the relay. You may be required to examine the internal workings of the relay box and clean that out too.
If the connectors are particularly dirty or corroded you may have to clean only the outside part. The process of cleaning away the dirt and grease entails a wire brush and also some baking powder. You may also need a blower and microfiber towel for the task.
No matter cause or circumstance, the best way to deal with a starting relay problem is to replace the relay. Doing so knocks out the issue once and for all.
Although long-lasting, the starter relay rarely has a lifespan exceeding 100,000 miles. It is thus worthwhile to have changed. Here’s how it’s done.
Replacing a bad starting relay
Starter relay replacement is a fairly easy and quick fix. There are several procedures to follow when installing a new starter relay. It all depends on which type of relay you are replacing.
How to safely 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. Typically, it is a black lid box in close range of the battery. If you’re having difficulty finding it, refer to your owner’s book. The booklet will direct you in locating your starter relay.
- Step 3: Disconnect the starter relay.
Fender wall relay
This starter relay is mounted directly on the fender or firewall. Takedown is simple:
- Step 1: Disconnect the battery terminal with a large wrench or pliers.
- Step 2: Disconnect the leads going to the relay terminals and remove the nuts with a catchable wrench or socket. .
- Step 3: Remove the mounting screws holding the relay to the fender.
Installing a starter relay
Installing a fuse box starter relay is one of the most user friendly DIY jobs. There are no bolts, screws, or nuts too tight – and nothing to worry about.
Compare both new and old relays. If you’re confident that they’re identical, 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 reattach the battery terminals.
Follow the steps below and install a fender wall relay;
- Hold and place the relay against the installation point. Plugin the screws and tightly screw them to fasten the relay. Connect the starter circuit leads to the battery terminals.
- Make sure you connect the right wire to the right post.
- After the installation is done, give yourself an assurance of doubt and recheck the work. Make sure the cables and connector is intact on the fender wall relay
- Finally, check the starting system. If it works pat yourself on the back and wade off. But then, if you’re not really the DIY kind (of person), and in doubt of this guide, don’t hesitate to contact an expert.
FAQs.
Q: Does a relay click when it’s bad?
A failing or bad starter relay will not produce enough electrical current to activate the starter motor.
Whatever number of times you revolve the engine, it’ll not start. A faulty starter relay will give a click sound when you turn on the ignition.
Q: Where is the starter relay switch located?
Starter relays are commonly mounted on the engine bay, but not on the engine block. You can trace the starter relay from the fuse box by following the big wire from the positive battery terminal. Most cars will have the relay close to the battery sitting in a box with a black lid.
Q: How do you check if a starter relay is working?
A multimeter is the only tool you need to check a starter relay. Get a multimeter and set it on an ohm’s scale. Place one of the probes on the ground cable and the other probe on the ignition circuit terminal.
A good relay should be operating under 5 ohms. Anything above 5 ohms means you have a bad starter relay that should be replaced.
Final Thoughts
It is important to make sure your starter relay is in good order. Think of it as part of your automotive health. So knowing the signs of a bad starter relay and how to fix it will keep you from getting stuck in the middle of nowhere.
I believe I’ve helped you with all the information you need in fixing your starter relay problems. You now know the functions, causes and signs of a starter relay. You can now diagnose, fix or replace a bad starter relay.