Car Won’t Start? 20 Reasons Why Your Car Won’t Start

It’s a beautiful day outside. The sun is shining and the weather is perfect. You slide into your car, ready to start your busy day, when uh oh! your car won’t start.

There are many reasons why your car won’t start. Before calling for help, there are things you can check yourself. For starters, make sure the steering wheel isn’t locked.

An empty gas tank is another simple reason why your car won’t start. If you were low on fuel before (or your gauge is broken), it’s possible you’re just on “E.” Take a look at some common reasons why you’re stuck and what you can do to get back on the road.

Why Your Car Won't Start

What To Do If Your Car Won’t Start?

When your car breaks down and you’re on a busy road, this can be a scary experience. If you don’t have an emergency kit in your car, there are a few things to do to fix the situation. First, call roadside assistance to get you and your car to a safe location (preferably an auto shop). Then, you or the mechanic will need to figure out why it’s not starting. Here are a number of reasons why your car won’t start:

#1. Bad or dead battery.

A dead battery is the most common reason why your car won’t start. The battery is what the car uses to provide electrical power to the entire car and electrical components (e.g., lights, radio, etc.). While the vehicle is running, the alternator charges the battery. If the battery is not charged sufficiently, you will not be able to start the car or use any electrical components.

Signs & Symptoms of a Bad Battery:

There are some telltale signs of a bad battery. Look for these issues when your car is hard to start, starts inconsistently, or there’s no sound or light on when you hit the ignition.

  • Dashboard and interior lights are dim
  • Windshield wipers are slow or barely move at all
  • Electric windows slowly open or close
  • Battery and/or cables are corroded
  • Radio won’t turn on
  • Swollen battery

You could have a bad battery if the cranking of the engine is sluggish, there’s no sound or interior lights when you try to start the vehicle, your car starts inconsistently, or you can start it with jumper cables but the vehicle will not start again after being shut off. A loose or corroded connection can also cause issues.

How to Tell if Your Battery Is the Problem? If jump-starting works, then it’s probably your battery. The question then is, how old is that battery? If it has been starting your car or truck for more than four years, it could just be at the end of its lifespan. But a battery can also be drained when the lights are left on when the car isn’t running.

#2. Bad Battery Connection.

If its not a battery problem the next thing to check is your battery connection cables. If they look damaged or loose, the car might not be able to pull electrical power to start the car engine.
There is also the possibility of a corroded battery.

If you see a lot of brown/white/blue/green discharge around the battery connectors, you’ll need to get this cleaned. We recommend you go to a professional but here is where you can find out how to clean corroded battery terminals.

Make sure your car is OFF before touching the battery area.

#3. Faulty starter motor.

A broken starter is another common reason your car won’t start. A starter is an electrical motor that is connected to the battery. Its role is to set the engine (i.e., pistons, crankshaft, etc.) in motion when you turn the ignition switch on.

Once the engine starts and is in motion, the starter’s job is complete. If the starter goes bad, the engine will not crank properly or may not crank at all when you turn the ignition key on.

If you hear a clicking noise when you try to start your vehicle, a broken or weakened starter could be the reason why your car isn’t starting. This is very similar to the bad ignition switch example listed before.

Some common symptoms include:

  • The car is not starting when turning the ignition key.
  • Hear a loud clicking sound when turning the ignition key, but the engine does not start.
  • Very noisy when trying to turn on your car.

#4. Bad Alternator.

If you can start the car but it stalls or you’re experiencing interior lights that start out bright and then dim, the alternator could be the culprit.

Gas and diesel-powered vehicles use an alternator to keep the battery charged and run all of the electric systems, such as your radio, windshield wipers and comfort controls. Essentially, the alternator is a small generator that creates electricity from a belt directly connected to the engine.

As long as that alternator is creating electricity and the battery is good, your car should start and stay running. If the vehicle won’t crank or start but the headlights are still working, look to problems with the starter or other parts of the engine.

How to Tell if Your Alternator is the Problem?

While it can be difficult to tell if your alternator is creating electricity without a lot of specialized tools, there are some signs to watch for:

  • Trouble starting the vehicle
  • Frequent stalling after you’ve started your vehicle
  • The squealing sound coming from the engine that gets louder when you use the heater or sound system (this may be your alternator bearings)
  • Interior and exterior headlights that seem to dim and brighten
  • Check-engine light or battery indicator light illuminated on your dashboard
  • The vehicle immediately stops running after a jump start

Here’s a quick way to diagnose your alternator: Get the vehicle started (if possible). Then turn on your radio and tune to a low number on the AM dial. Finally, rev the engine. If you hear a whine or the sound goes fuzzy when you hit the gas, your alternator is probably failing.

#5. Faulty Immobilizers.

If you try to unlock your car with your key fob and it doesn’t work, this may mean there’s a problem with the engine immobilizer. This can also cause a problem starting your car if the fob is unable to send a security code to the engine immobilizer.

Knowing why your car won’t turn on is a good first step toward repairing it, but sticking to a car maintenance schedule can help prevent issues from arising in the first place.

#6. Bad ignition switch.

The ignition switch is another step on the road that leads from turning your key to starting your engine. It plays a crucial role between your battery and starter motor, carrying power from the battery to the engine.

If you have a bad ignition switch, you won’t hear the starter motor working to start the engine. You also might experience some electrical issues, since the ignition switch effectively activates your car’s main electrical systems. Flickering or dying dashboard lights are a prime example. You may also have difficulty turning your key in the first place.

#7. Bad timing belt.

Your timing belt is another component that is integral to a functioning engine. The timing belt rotates the engine’s cam and crankshaft in unison, causing the cylinders to fire at the appropriate times.

If something is wrong with your timing belt, you may hear ticking noises from your engine or strange disparities in your engine’s revving, or your engine may not turn over. Replacing your timing belt is a piece of maintenance that needs to be performed on a semi-regular basis, so if you notice any issues that could be tied to it, don’t hesitate to call your mechanic.

#8. Clogged fuel filter.

If fuel can’t reach your engine, your car is going to have a difficult time burning it. As obvious as that sounds, you might not realize that the fuel filter is preventing your car from starting.

You may notice an array of fuel-related troubles, ranging from sputtering to poor gas mileage and, of course, difficulty starting. Your fuel filter should be replaced every 30,000 miles, so if yours is coming up on that milestone and your car doesn’t start, it’s worth checking and replacing.

#9. Broken Distributor Cap.

Its not always your starter motor or spark plugs as the reasons why your car won’t start. Common reasons include a broken distributor cap. This routes electricity after ignition back to the spark plugs. If your car starts you can still have a faulty cap.

If you hear noises, see a check engine light, or your engine is misfiring, have your mechanic check your distributor cap and all your car starting parts.

#10. Stuck Steering Wheel.

If you get into your car and can’t even turn the key in the ignition to start it, your steering wheel has locked as an anti-theft protective measure. This issue is less common, especially with the rise in digital keys. Luckily, there’s a straightforward fix.

Insert the key into the ignition and turn it slightly. Then, turn the steering wheel left and right. After this, the wheel should unlock, and you’ll be able to start your car.

#11. Your Car Isn’t In Park Or Neutral.

If your car won’t start, it might not be in park or neutral. It could be that your car is in gear. Try to push on the brake pedal and move the car into park. If your vehicle is already moving shift the car to neutral then attempt to start the car again.

If you can turn your key in the ignition while your car is in drive immediately take it to a professional for a fix up.

#12. Dead Key Fob Battery.

On newer vehicle models that require a key fob to start the engine, sometimes the vehicle won’t recognize the fob if the fob is dead.

Vehicles where you turn the key don’t have these starting problems. You’ll need to replace the battery in the fob before you can start your car. Look for a coin or a screwdriver to open the battery cover, you can find more on changing fob batteries here.

#13. Empty Fuel Tank.

First off, don’t be too embarrassed. You aren’t the first or last driver to let your gas level get way too low before filling things up again. If your gas tank is completely empty, the best way to get your car on the road again is filling it up! Pick up a can of gas at a gas station and fill ‘er up.

Also, try to avoid riding too close to empty during the colder months. When your car is sitting outside in cold winter weather, the wet air in your gas tank could have too much moisture and freeze.

When that air freezes, you’re in trouble. The more gas that you keep in your tank, the less air and moisture will be inside.

#14. Faulty Fuse.

If your car won’t start it may be due to a bad fuse. Car fuses are easily accessible and can be found under the hood and beneath the steering wheel of your car. The car’s electrical system all runs through the fuse boxes.

You can replace a blown fuse but if the blown fuse is bad enough, some of the wiring might be damaged. This can prevent cars from starting. You can find the map to your vehicle’s fuse box in the owners manual.

#15. Old Spark Plugs.

Spark plugs are a common culprit of why a car won’t start. Defective spark plugs lead to misfires, low gas efficiency, and other car problems. If your car is running awkwardly before you notice that it won’t start.

This could be a good indicator that it is the spark plugs. If the engine cranks & you here a clicking sound but the engine doesn’t turn over, this could be defective spark plugs.

#16. Failed Fuel Pump Relay.

The car’s fuel system is paramount to the engine starting. If you don’t hear noise from the fuel pump in the fuse box, this could be the reason why your car won’t start.

If you have trouble starting your vehicle and have these signs there might not be enough fuel drawn to the combustion chamber.

Replace the fuel pump relay fuse or swap it with a different relay fuse and check if the engine turns this time. If it starts, take it to a mechanic to make sure that was the only thing wrong. You can find the fuse box in the owner’s manual.

#17. Fuel Pump Issue

Your fuel pump works with your car’s gas engine to initiate the combustion that starts the car. Like a bad battery, you can tell when it’s going bad if the car takes a while to crank up. Other signs include if the check engine light comes on or if you’re having trouble accelerating the vehicle.

A car’s engine consists of myriad components. Make sure to get your vehicle inspected if the check engine light comes on or you experience any of the stated issues to ensure it’s safe to drive.

#18. Engine Problems.

Problems with the mechanics of your car’s engine can stop the car from starting. The main culprits are usually the crankshaft or the timing belt and timing chain. Altogether, they make up over 3% of non-starting cars we see.

This could be the problem if the engine won’t turn over or starts and stalls.

#19. Cable Wiring Problem.

There is a large cable that directs electricity to the car’s body. All cars have these ground wires that run through the body of the vehicle.

Common symptoms may include hard starting, there may be a dead battery, the engine can feel off, there may be flickering dome light, a damaged throttle, sporadic sensor failure, and more if there’s a ground cable issue. You’ll typically be able to see a large damaged wire near the car’s engine.

#20. Low AdBlue.

If you’ve run out of AdBlue, you won’t be able to restart the engine. You may have to call out a mechanic as some car models need software to restart them.

It’s easy to avoid running out though – your car will show you a warning with a countdown on the dashboard to give you time to top up.