What happens when you turn the key is the first useful detail.
“Won’t start” can describe several very different failures. The fastest way to narrow it down is to describe exactly what the engine and electrical system do when you try.
Which situation sounds like yours?
Nothing turns the engine.
Start with battery state, battery connections, the starting circuit, interlocks, and whether the starter is receiving what it needs.
The starter tries, but struggles.
Low battery voltage, poor connections, excessive starter load, or another starting-system problem may be involved.
The engine turns but never runs.
The diagnostic direction changes toward fuel, ignition, engine-speed signals, air, compression, security systems, and any stored codes.
Choose the more specific starting symptom
Useful details to notice before trying again
- Do the dashboard lights come on normally?
- Is there one click, rapid clicking, slow cranking, or normal-speed cranking?
- Did the problem happen suddenly or get worse over several starts?
- Was the battery recently discharged, replaced, or disconnected?
- Are there warning lights or OBD-II codes?
- Does it happen only cold, hot, after rain, or intermittently?
Do not overlook basic safety
Do not repeatedly crank an engine while there is a strong fuel smell, smoke, damaged wiring, or another sign of an unsafe condition. If the vehicle is in traffic or another dangerous location, personal safety comes before troubleshooting.
Ready to narrow it down?
Start with the vehicle, symptoms, or trouble code you already have. CarCause will guide you through the next useful check.