Stuck with a car that won’t start?
While you’d want to resolve the issue immediately, you need to find out why it won’t start.
Is it a dead battery, or does the alternator need replacing?
Maybe there’s an issue with your timing belt.
Read on to explore the most common reasons your car won’t start and get solutions for each starting problem.
This Article Contains:
- 16 Reasons Why Your Car Won’t Start
- Dead Car Battery
- Bad Alternator
- Bad Battery Connection
- Ground Cable Wiring Problem
- Empty Fuel Tank
- Your Car Isn’t in Park or Neutral
- Jammed or Locked Steering Wheel
- Faulty Fuse
- Bad Starter Motor
- Bad Fuel Pump Relay
- Faulty Ignition Switch
- Dead Key Fob Battery
- Bad Spark Plug or Broken Distributor
- Timing Belt Needs Replacing
- Clogged Fuel Filter
- Low Diesel Exhaust Fluid
16 Reasons Why Your Car Won’t Start
Even with regular maintenance, various issues can crop up and prevent car start-ups.
Here are some of the most common starting issues and their fixes:
1. Dead Car Battery
Your car battery stores the power necessary to run your vehicle. If it’s dead, your car won’t start.
How can you tell if you have a battery problem?
Look for these signs:
- No response at ignition
- Illuminated check engine light
- Dome and interior lights don’t turn on
- Non-functioning headlights
Solution:
Use jumper cables or a portable jump starter to get your car started.
Don’t know how to jump-start a weak battery?
Call a mechanic or roadside assistance for help.
They’ll test your car battery with a battery tester or multimeter. If the voltage is low, they’ll charge the weak battery or install a new battery.
2. Bad Alternator
If your car battery’s dead, it’s likely due to a bad alternator.
The alternator distributes electricity and recharges the car battery. So, any issues with the charging system will prevent the car from starting.
How do you know you have a faulty alternator?
Watch out for these signs:
- Dome or interior lights start bright, then go dim
- Battery or check engine light turns on
- Burning rubber smells coming from the alternator belt
- Stereo system issues
Solution:
If the alternator is in bad shape, it’s best to get an expert diagnosis and replacement.
3. Bad Battery Connection
Cars won’t start if the battery cable connections are ripped or loose. They’ll also fail to start if the battery terminals are corroded, as it blocks the electricity flow.
Solution:
Turn off your car and try twisting the cable connections at the battery terminal. If they move, the battery terminals are loose and need tightening.
However, if there’s corrosion, clean the terminals before reattaching or replacing them. Since this requires working with metal tools around a car battery, it’s recommended to leave it to a professional.
4. Ground Cable Wiring Problem
The ground cable is the heavy black battery cable that connects the battery’s negative terminal to the car’s body. It’s also called the negative battery cable.
This cable is the foundation of the entire vehicle’s electrical system. If it’s damaged, your car won’t start because the power flow will be cut off.
How can you identify ground cable problems?
Common symptoms include:
- Dim or flickering dome light
- Defective fuel pump
- Dead battery
- Sporadic sensor failure
- Electrical devices turning on and off
- AC compressor clutch doesn’t engage
- Damaged throttle or cables
- Hard starting
Solution:
Pop the hood to visually inspect the ground cable for an electrical problem or damage. If it looks worn out, get it replaced immediately.
5. Empty Fuel Tank
If your gas tank is empty, your car won’t start, so check your fuel level regularly to ensure there’s enough fuel before heading out.
In cold weather, an empty gas tank can also cause the fuel line to freeze due to the formation of water vapor inside it, preventing the car from starting.
Solution:
If your car frequently runs out of fuel, have a mechanic check for leaks or a broken fuel gauge. To avoid frozen fuel lines, keep your gas tank half full in cold weather and use a fuel line antifreeze additive.
Note: Sometimes, older cars with carburetors won’t start when the engine is flooded with fuel. To fix this, press and hold the gas pedal to the floor while cranking the engine.
6. Your Car Isn’t in Park or Neutral
Your car won’t start if it’s in gear. It has to be in ‘Park’ or ‘Neutral.’
Solution:
Move the gear to Neutral or push the brake pedal to see if your car starts. For manual transmission vehicles, push down the clutch pedal.
Note: If your car starts in drive gear, it may indicate a bad neutral safety switch, which is dangerous. So, seek professional help immediately. Attempting engine or transmission repair can be tricky and expensive, especially without auto insurance.
7. Jammed or Locked Steering Wheel
If you can’t turn your key, it might be due to a jammed steering wheel — an anti-theft feature that activates when someone turns the wheel without the car running.
Solution:
To release the steering lock, gently wiggle the steering wheel while turning the key. Once the car starts, the steering wheel should unlock.
8. Faulty Fuse
Car fuses protect the electrical system in your car. However, if you have faulty wiring or damaged fusible links, your car won’t start.
Why?
A damaged or blown fuse prevents power from reaching the starter relay, which is needed to provide the spark, ignition, and power to move your vehicle.
Solution:
Check your car owner’s manual to locate the fuse box. Then, examine for a blown fuse or visible wire damage. If you can’t access it, call an auto repair mechanic for help.
9. Bad Starter Motor
The starter motor is a device that turns over the internal combustion engine during ignition.
It has a smaller cylinder-like component attached to it — the starter solenoid — which transfers the electrical current from the battery to the starter motor to crank the engine. If there’s a starter problem or the solenoid is broken, your car won’t start when you activate the ignition.
How can you tell if the starter motor or solenoid is faulty?
Here are some signs:
- The car engine cranks slowly or doesn’t start
- You hear a clicking noise on turning the key
Solution:
Get the bad starter or solenoid replaced by a professional.
10. Bad Fuel Pump Relay
The fuel pump relay is an electrical component in the car’s fuse box. It relays the power required by the fuel pump to draw the right amount of fuel to the combustion chamber.
Some tell-tale signs of a faulty fuel pump relay are:
- The engine stalls or won’t start
- Check engine light comes on
- No noise from the fuel pump
- Inconsistent acceleration
Solution:
The fuse box typically has more than one relay for different functions. To confirm if you have a bad relay, swap their positions and check if the issue is resolved.
Note: This method won’t work if multiple relays are faulty, so get your fuel system checked by an auto mechanic.
11. Faulty Ignition Switch
The ignition switch moves power from the battery to the car’s components. When the switch is faulty, power won’t reach the starter motor or ignition system, and your car won’t start.
If you have a bad ignition switch, you’ll notice:
- The car key won’t turn
- No noise from the starter motor
- Flickering dashboard lights
- The instrument panel won’t light up
- The switch is always in the on position and powering the fuel pump
Solution:
The easiest way to deal with a bad ignition switch is to carry a light keychain. A heavy keychain strains the ignition switch because it’s located right behind the ignition lock cylinder where you insert your car key.
12. Dead Key Fob Battery
If the engine crank fails when you press ‘Start’ in your push-start car, you may have a dead key fob battery. This prevents the button from receiving a signal, so your car won’t start.
A faulty engine immobilizer can also prevent your vehicle from starting by failing to send a security code. You may notice a key symbol or a rapidly flashing dashboard light.
Solution:
Replace the dead key fob battery by opening the cover with a small screwdriver. The battery will look like a silver coin or button. Match the numbers on the battery to find the right replacement.
If it’s an immobilizer issue, hold the fob against the start button or use a spare key. If your car doesn’t start or you don’t have a spare key, get a new key or call a mechanic.
13. Bad Spark Plug or Broken Distributor
If you have a good battery and enough fuel pressure, but your car doesn’t start, you might have a bad spark plug.
Why?
A bad spark plug will prevent fuel ignition and vehicle start-up.
Signs of a bad spark plug include:
- Reduced fuel economy
- Acceleration issues
- Engine misfires
- Rough idling
If your spark plugs are fine, but the car doesn’t start, the distributor cap or rotor might be broken.
What are they?
A distributor delivers electricity to spark plugs, which ignites the air-fuel mixture. It also directs high voltage current from the ignition coil to the spark plugs.
The distributor cap has a rotor that protects its internal parts and holds the contacts between the rotor and spark plug wires. If the cap isn’t tight or the rotor doesn’t work properly, the spark won’t travel.
Solution:
Bad spark plug signs aren’t easy to spot and can often occur alongside other vehicle issues. Have your vehicle inspected by a mechanic to confirm bad spark plugs and distributor.
14. Timing Belt Needs Replacing
The timing belt is a rubber belt that synchronizes the cam and crankshaft. If it fails, your car’s engine won’t function.
Your timing belt needs replacement if:
- You hear the starter motor engage, but the engine doesn’t turn over
- There’s a clicking sound coming from under the hood
- The timing belt breaks while the engine is running
Note: Some cars may have a timing chain instead of a belt because it lasts longer. However, it can still break and require service.
Solution:
Get a mechanic to replace the broken timing belt or chain.
15. Clogged Fuel Filter
Fuel filters help prevent debris and rust particles from entering the fuel. While they help deliver clean fuel from the gas tank to the fuel injector, they risk getting clogged over time.
A completely clogged fuel filter will prevent the vehicle from starting due to reduced fuel pressure. This can also happen if the fuel injector nozzle is clogged.
Solution:
Use high-quality gasoline to minimize debris in your fuel system. Check your owner’s manual for fuel filter replacement intervals, and have them changed by professionals to avoid severe clogging.
16. Low Diesel Exhaust Fluid
If your diesel car doesn’t start, it might be due to low diesel exhaust fluid (DEF) levels. The electronic control unit prevents the engine from restarting until the fluid is topped up to control emissions.
Solution:
Refill the fluid and start the car again. If it doesn’t start, your mechanic will reset the system.
Why?
A system reset helps maintain the efficiency and compliance of the Selective Catalytic Reduction (SCR) system. Issues like low DEF can trigger incorrect sensor readings and affect vehicle performance.
Get Your Car Back on the Road with AutoNation Mobile Service
Car starting issues can stem from a faulty alternator, a starter problem, or a bad fuel pump. But before you order parts, you must pinpoint the exact cause of the issue.
Need help to diagnose car problems?
Schedule service with experts from AutoNation Mobile Service.
We’re a mobile car maintenance solution offering a 12-month, 12,000-mile warranty on all auto repair services.
Contact us, and our experts will resolve your starting issue right from your driveway.