17 Possible Reasons Why Your Car Won’t Start (+ How to Fix)

Starting a car may seem simple, but there’s more that happens under the hood to get the engine running. So, if your car won’t start, several factors could be at play.

Whether it’s an empty fuel tank or a dead battery, identifying the cause is crucial to getting your car back on the road.

Read on to uncover 17 reasons your car won’t start and how to fix them.

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17 Critical Reasons Your Car Won’t Start (+ What to Do About It)

17 Critical Reasons Your Car Won’t Start (+ What to Do About It)

Here’s a list of some common car starting issues and their solutions:

1. Bad Battery

The car battery sends an electrical signal to the starter, which then cranks the engine. If the battery is weak or drained, the engine won’t turn over. Weak or failing car batteries can also make it harder to start a car in cold weather conditions.

Solution: You can jump-start a dead car battery with the help of jumper cables and a working car’s battery. But if you don’t have jumper cables handy, call roadside assistance for help.

Since this is only a temporary fix, it’s best to visit a car repair shop to have the failing battery tested. The mechanic will look for loose connections and corroded terminals. They’ll also use a multimeter to check the battery voltage. If the battery is severely worn, they’ll replace it.

NOTE: Car insurance typically doesn’t cover car batteries unless the damage is caused by an accident or vandalism. Check with your car insurance provider before visiting a mechanic.

2. Poor Battery Connections

Loose, faulty, or corroded connections can create resistance in the circuit, preventing power from reaching the ignition components and making it difficult for the engine to start.

Similarly, a loose ground wire can disrupt the current flow and cause starting difficulties. You may also notice issues like a dead car battery or an illuminated Check Engine Light.

Solution: Check the battery cables and try to move them gently. If they’re loose or dirty, disconnect them (negative connector first) and clean them with a cloth. Once cleaned, reconnect them securely (positive connector first) and restart your car.

Also, visually inspect the ground wire for damage. If it appears worn out, replace it immediately.

3. Bad Alternator

The alternator charges your car’s battery and powers its electrical systems. If it fails, your battery won’t recharge, and the engine won’t have enough power to start. You might also notice a Check Engine Light, dim dashboard lights, or difficulty starting the car in cold weather.

Solution: If your car doesn’t start due to a bad alternator, call a mobile mechanic for a professional diagnosis and replacement.

4. Blown Fuse

Fuse boxes protect the car’s electrical system. When a specific fuse blows, the systems connected to it stop working. So, if a fuse related to the ignition, starter, or battery is blown, your car won’t start.

Solution: Replace the faulty fuses by referring to your owner’s manual to locate the fuse box (usually under your car’s hood or beneath the steering wheel). But if you can’t find or access it, call a mechanic for help.

5. Bad Starter

Car makes a clicking noise when you turn the key but won’t start?
This could indicate a damaged starter.

The starter motor engages the pinion gear with the engine’s flywheel to start your car. If you have a faulty starter motor or a burnt starter solenoid, the engine won’t start when you turn the key or press start.

Solution: If you have a faulty starter solenoid or broken starter, have a mechanic replace them.

6. Faulty Ignition Switch

The ignition switch controls the power flow between the battery and the starter motor. If it fails, the ignition system and starter motor won’t work, preventing engine cranks.

Solution: Call a mobile mechanic to replace the ignition switch and use a light keychain to avoid straining the switch in the future.

7. Dead Key Fob Battery or Malfunctioning Immobilizer

In newer vehicles with key fobs, the car doesn’t start if the fob’s battery is dead. Moreover, a faulty immobilizer can stop the car from recognizing the key fob, especially if the battery is low.

Solution: Replace the key fob battery with a compatible coin battery. If the problem is with the immobilizer, try holding the fob against the start button. You can also use a spare key, as the problem may be with the specific fob or its signal. If you don’t have a spare key, purchase a new one.

If these methods don’t work, it could indicate a more serious issue with the immobilizer system itself, which will require professional diagnosis or reprogramming by a technician.

8. Your Car Isn’t in Park or Neutral (For Automatic Transmission)

For safety reasons, your car won’t start if it’s in gear instead of park or neutral.

The neutral safety switch stops the engine from starting when the vehicle is in gear to avoid the car lurching forward or starting in reverse. If your car starts in any gear other than park or neutral, it means the neutral safety switch is broken.

Solution: Press the brake and ensure the car is in park before starting it. If your neutral safety switch is faulty, visit an auto repair mechanic immediately.

9. Jammed Steering Wheel

Most cars have an anti-theft safety feature that locks the steering wheel when the vehicle is off. If you try to move the steering wheel after turning the car off, the lock activates, and your key won’t turn until the steering lock is released.

Solution: To undo the steering lock, gently wiggle the steering wheel back and forth while turning the key. Once the car starts, the steering wheel will unlock on its own.

10. Empty Fuel Tank

If your gas tank is empty, the fuel injectors can’t supply fuel to the engine, and your car won’t start. Moreover, if your fuel gauge is broken, you might run out of gas without realizing it, as the indicator won’t show the correct fuel level.

Solution: Fill the gas tank with at least two gallons of fuel. If your fuel gauge isn’t working properly, have a mechanic check and repair the car part.

11. Clogged Fuel Filter

A fuel filter keeps dirt and debris from entering the engine. If it becomes clogged, it restricts fuel flow to the engine, causing starting problems.

Solution: Change the fuel filter every 30,000 miles, and use high-quality gasoline to reduce debris buildup in the filter.

12. Bad Fuel Pump Relay

A fuel pump relay is a small car part (electrical switch) that controls your fuel pump. If the car isn’t starting and you suspect fuel isn’t reaching the engine, the fuel pump relay could be the problem.

Solution: Try a different relay from another circuit (like the horn or any non-essential system) to see if the engine starts. If the pump starts working, swap the bad fuel pump relay for a new one.

13. Engine Intake Problems

Faulty engine intake components, like the fuel injector, throttle body, and fuel pressure regulator, can prevent the car from starting. Additionally, too much fuel entering the engine can cause a flooded engine, making it hard for the engine to crank.

Solution: Call a mechanic to have the fuel injector, throttle body, and fuel pressure regulator inspected and replaced.

14. Bad Timing Belt

The timing belt connects and synchronizes vital engine parts to ensure they move together. If the timing belt is faulty, you may hear the starter motor engage or make a ticking noise, but the engine won’t run.

Solution: Have a mechanic replace the timing belt and get it checked routinely to avoid severe engine damage.

15. Faulty Crankshaft Position Sensor

The crankshaft position sensor monitors the position and speed of the engine’s crankshaft. If it fails, the Engine Control Unit (ECU) won’t know when to inject fuel or fire the spark plugs, which can prevent the car from starting.

Solution: Call a mechanic to inspect and replace the faulty crankshaft sensor.

16. Bad Spark Plug or Broken Distributor Cap

Worn-out spark plugs can cause poor fuel efficiency, sluggish acceleration, and difficulty starting. If your spark plugs are fine, a bad distributor cap could be the culprit. The distributor cap transfers power from the ignition coil to the spark plugs, and if it’s damaged, it can cause misfires or prevent the car from starting.

Solution: Have a mechanic inspect and replace the faulty spark plug or distributor cap to ensure the engine cranks properly.

17. Low Diesel Exhaust Fluid (DEF)

In diesel vehicles, low DEF levels (like AdBlue) can lead to starting issues because the fluid is essential for the Selective Catalytic Reduction (SCR) system to function.

The SCR system reduces harmful emissions by converting nitrogen oxides into harmless nitrogen and water. Without enough DEF, the SCR system can’t function, causing the engine to lose speed and eventually stop running.

Solution: Top off the DEF and start your car. If it doesn’t start, a mechanic will have to reset the system to keep the SCR system running smoothly. Resetting the system is essential because low DEF can trigger faulty sensor readings, affecting car performance.

Get Your Car Back on the Road with AutoNation Mobile Service

Nothing’s more frustrating than a car that won’t start. Whether it’s a damaged starter or a fuel system problem, fixing it should be your priority.

Instead of worrying about calling roadside assistance and towing your car to a mechanic, let AutoNation Mobile Service bring the repair shop to you.
We’re a mobile auto repair solution that offers easy online bookings, upfront pricing, and a 12-month, 12,000-mile warranty on all car repair services.