Symptom guide
Car Won't Start
A practical guide to the most common reasons a car will not start, from battery issues to fuel and ignition faults.
Quick answer
Most no-start problems come from a weak battery, poor battery connection, failed starter, missing fuel pressure, or no ignition spark.
Most likely causes
- Weak or discharged battery
- Corroded or loose battery terminals
- Failed starter motor or starter relay
- Fuel pump not running
- Ignition or immobilizer issue
Basic driver checks
- Listen for a single click, rapid clicking, or silence when turning the key.
- Check whether headlights are bright or dim.
- Look for corrosion on the battery terminals.
- Confirm the gear selector is in Park or Neutral.
- Notice whether the security light stays on.
DIY diagnostic path
- Measure battery voltage: about 12.6V is fully charged, while much below 12.2V may struggle.
- Try a jump start if the battery is weak and cables can be connected safely.
- If the engine cranks normally, move toward fuel, spark, and OBD code checks.
- If there is only a click, test battery cables and starter circuit before replacing parts.
Common mistakes
- Replacing the starter before testing the battery and cables
- Ignoring a loose ground cable
- Cranking until the battery is fully drained
What to tell the mechanic
Tell the mechanic whether the engine cranks, clicks, or does nothing. Mention any recent battery replacement, warning lights, or intermittent starting.