Lights on but the engine will not start? The common battery, starter, immobiliser, fuel and ignition possibilities, and what helps narrow it down.
Dashboard lights coming on does not prove the battery can deliver enough current to crank the engine. The most useful next clue is what happens when you actually turn the key or press the start button.
Rapid clicking often fits a low battery voltage or a poor high-current connection. Headlights and dashboard electronics need far less current than the starter motor, so they can still work when the battery cannot crank the engine.
A starter motor, starter solenoid, battery connection, earth strap, relay or control issue can all produce a no-crank condition. Automatic vehicles may also have selector or interlock issues, and some vehicles will inhibit starting if the immobiliser does not recognise the key.
That moves the fault away from the basic starter circuit. Fuel delivery, ignition, engine-speed sensing, immobiliser issues and other engine-management faults become more relevant.
Describe what your vehicle is doing and AutoAid can use the details, your saved vehicle and any OBD-II code to narrow the likely causes.
Start a diagnosisSee all symptom guides →Symptom pages are a starting point, not a confirmed diagnosis. If braking, steering, overheating, smoke or another safety-critical problem is present, stop somewhere safe and arrange professional inspection.