There’s nothing worse than a car that refuses to start.
You’re about to attend an important meeting or pick up your friends/family. But nothing happens when you try to start the vehicle but turn the ignition on.
And it feels strange because many vehicle accessories, such as interior lights and the car radio, work fine.
I’ve been in this situation many times. And from what I’ve seen, it can happen due to various reasons such as weak battery, corroded battery terminals, faulty starter, spark plug issues, etc.
In this post, we’ll discuss these issues in full detail.
How A Car Starts
Before discussing the actual issue, we should discuss how a vehicle starts, as it’s essential for diagnosing it.
In the beginning, the key is in the off position. At this point, all car accessories are powered by the battery.
When you turn on the key (or press the ignition button), an electrical signal is sent to the battery. The battery responds by sending a large amount of current to the starter motor.
The starter motor engages its pinion gear with the flywheel, which causes the latter to rotate with the crankshaft. Since the crankshaft is connected to the engine’s pistons, its rotation causes them to move up and down inside the cylinders.
The serpentine belt connects the alternator to the other side of the engine. When the crankshaft rotates, the alternator rotates with it and generates electricity. This electricity is used to recharge the battery (compensate for the power loss during the ignition process) and power the electrical systems inside the vehicle.
The alternator will continue to power all the car systems until the load is within its limit. After that, it’ll draw some power from the battery to compensate for the deficit.
When you turn off the engine, the alternator will stop working, and all car systems will draw power from the battery.
Car Won’t start (Clicking Sound)
There are a bunch of scenarios that’ll determine the culprit behind your vehicle not starting.
The first one is that you hear a clicking sound whenever you turn on the key or press the ignition button.
You should check the battery, battery terminals, and starter connections in such cases.
Weak Battery
The weak battery is the first reason why you’re getting a clicking sound when turning the key on.
If the battery is weak, it may not be able to provide sufficient power to the starter (as it’s pretty demanding), and you get a clicking noise in return.
To test whether your battery is in working condition, you’ll have to check it with a multimeter.
Connect the multimeter probes to the respective battery terminals. Then, set the multimeter to DC voltage mode and check the reading. It should be 12V-14V for most working batteries.
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Corroded Battery Terminals
Sometimes the problem is not with the battery itself but with the battery terminals and cables.
Corrosion can accumulate on the battery terminals over time (mainly due to electrolyte leakage, moisture, and contaminations). And can hinder the flow of electric power from the battery.
This hindrance, in turn, results in insufficient power delivery to the starter, and the vehicle doesn’t start.
Similarly, frayed and broken battery cables can’t efficiently supply electric power to the starter.
Therefore, you should also examine both before testing the battery. Make sure that the terminals are clean and tightly secure. And replace the battery cables if you notice any cracks or other types of damage.
Bad Starter Motor And Solenoid
If the battery works fine, you should check the starter motor next.
This component engages with the flywheel to rotate the crankshaft and start the engine. Although designed at last 100,000-150,000 miles, it can damage prematurely due to worn pinion gear, over usage, moisture, or improper installation.
These damages can cause the starter motor to not engage with the flywheel properly, which results in the vehicle failing to start.
Sometimes, the vehicle doesn’t start even if the starter works 100% fine. That’s because it has to rely on the starter solenoid to engage the pinion gear to the flywheel. If this solenoid goes bad due to corrosion or a damaged coil, the starter will not work.
Therefore, you should check these components with a multimeter and repair/replace them if necessary.
Bad Starter Motor Connections to the battery
The starter motor is connected to the battery through different electrical connections. If these connections get loose, damaged, or corroded, the starter will not receive power from the battery, and your car won’t start.
Therefore, you should physically inspect these connections and clean them if there’s any dirt or grime. Similarly, replace the wires if there’s any noticeable damage.
Car Won’t Start (No Click)
In the second scenario, you turn on the key, and nothing happens – you don’t hear any sound.
In such a situation, you should check the starter solenoid/motor and ignition switch.
Dead Battery
Unlike a weak battery, a completely dead battery can cause the vehicle not to produce any sound when turning the key on. That’s because it’s not providing any power to the starter that could make a sound.
Test the battery with the multimeter. If you got a 10.5V or below reading, it means the battery is fully dead. And that you should jump-start the vehicle and use a battery charger to revive it.
Ignition Switch
The ignition switch is essential to your vehicle’s ignition system as it controls the current flow to various parts of your car, including the starter motor.
Therefore, if the ignition switch is faulty, it may not send the power to the starter motor, and the vehicle will not start. Some other symptoms of a defective ignition switch include intermittent starting, difficulty turning the key, and engine stalling while driving.
As for the fix, you can physically check this switch (for any signs of wear, damage, or loose connections) or test the continuity between its connections using a multimeter. If it fails any of these tests, hire a mechanic to replace it.
Car Cranks but Won’t Start
Sometimes, the car cranks but doesn’t start. Fuel pump, fuel pump relays, or ignition/fuel system-related fuses in such cases.
Fuel Pump
The fuel pump is a crucial component of a vehicle’s fuel system as it transfers fuel from the tank to the engine (for combustion). These pumps can malfunction over time due to aging, contaminated fuel, or overheating.
This malfunction will cause the engine not to get any fuel, resulting in no combustion and no start.
Other symptoms of a faulty fuel pump include poor engine performance, stalling, and hesitation during acceleration.
Fuel Pump Relay
The fuel pump relay is a switch that determines whether the pump will receive power. If this relay starts to malfunction, the fuel pump will not be able to get any power and will not send fuel to the engine.
You should check this relay with a multimeter to confirm whether that’s the case.
Here’s how it goes:
- Locate the relay. It’s usually found in the main fuse box. You’ll need to check the fuse box diagram to identify it.
- Pull it out of the fuse box and detach it from the connector.
- Identify its pins. These relays usually come with 4-5 pins, numbered pin 85, pin 86, pin 87, etc.
- Set the multimeter to continuity mode and connect its probes to pins 85 and 86.
- You should hear a beep sound. Otherwise, the relay is not working.
- After that, connect multimeter probes to pins 30 and 87.
- You shouldn’t get any beep sound this time, as there’s no continuity.
- Lastly, run a jumper wire from the battery’s positive terminal and connect it to pin 85. Similarly, run a jumper wire from the battery’s negative terminal and connect it to pin 86. This step is necessary to activate the relay.
- Again connect multimeter probes to pins 30 and 87.
- This time, there should be continuity.
If the relay fails in any of these three steps, it’s not working and should be replaced.
Blown fuses
Similar to faulty relays, blown fuses can cause a vehicle to crank but not start.
This includes the fuel pump fuse, ignition system fuse, fuel injector fuse, or main relay fuse. These fuses protect their respective components and wirings against short circuits/overloads.
If there is a short circuit, these fuses break apart and open the circuit. As a result, those components will not get power and won’t do their job in the ignition process.
Therefore, if you’ve checked for all issues we’ve discussed, it’s time to check the fuses too. Like relays, these fuses can be checked by a multimeter. All you need to do is to pull the fuse out of its slot, set the multimeter to continuity mode, and connect its probes to the fuse pins.
If you hear a beep, it means the fuse is working. Otherwise, it’s blown and should be replaced.
Conclusion
These are some of the common reasons why your vehicle doesn’t start. Of course, checking for all of these issues is a lengthy task. But it’s critical at the same time as we can’t find the root cause of this issue otherwise.
If you cannot diagnose the issue after following all the steps, I suggest consulting a certified mechanic. That’s because this problem looks a little too deep for DIY.
Frequently Asked Question
Can A Car Battery Be Dead If The Radio Still Works?
Yes, a battery can be considered too weak or dead even when powering the radio or lights. That’s because these components require much less power than the starter motor.
How Do You Tell If It’s The Starter Or The Battery?
If your vehicle has power but not starting, you should turn on the headlights and notice their intensity when you try to start. If the headlights go dim when you turn on the key, it indicates issues with the battery or its connections. On the other hand, if the headlights remain constantly bright, the problem is with the starter.
Will A Blown Fuse Keep A Car From Starting?
If a fuse related to some component in the ignition/fuel system, such as a fuel pump fuse or ignition fuse, is blown, it can cause the vehicle not to start. That’s because the blown fuse will cause that component not to turn on and perform its part.
How Can I Test My Car Starter?
You can test the starter with a visual inspection or a digital multimeter.
What Sensors Can Cause A Hard Start?
Many sensors in your car can cause a vehicle to start hard (or even not start at all) if they malfunction. These sensors include a crankshaft position sensor, throttle position sensor, mass airflow sensor, fuel pressure sensor, camshaft sensor, etc.
Can A Bad Starter Drain A Battery?
A bad starter can cause prolonged cranking or make the starter solenoid stuck. Both issues can draw more power from the battery, draining it faster.
