Car Won't Start? What to Check First, in Order

Start here: what happens when you turn the key?

Sit in the car, turn the key to start or press the button, and watch the dashboard while you listen. Then find your symptom.

Car won't start, no lights, no sound at all

The car isn't getting power. In order of likelihood: the battery is completely flat, a battery terminal is loose or corroded, or a main fuse has blown. Open the hood and look at the two battery posts. White or blue-green crust around them, or a clamp you can wiggle by hand, can be the whole problem. If the interior lights are dead too, that points the same way.

Car clicks but won't start: rapid clicking

That fast clicking, like a playing card in bicycle spokes, is the classic low battery. There's enough charge to snap the starter solenoid in and out, but not enough to turn the engine. A jump start will almost always get you going. What it won't tell you is why the battery went flat. If you left a light on, the battery's probably fine. If it died on its own, it's either near the end of its life or the alternator isn't charging it. If it happens twice, stop jump starting it and get it tested.

Car won't start but the battery is good: one loud click

You hear a single heavy click, the dash lights stay bright, and nothing turns over. The battery has the power, and the starter motor isn't using it. Usually that's the starter itself or its solenoid, sometimes a bad connection on the thick cable running to it. A jump start won't help, which is a handy way to confirm it.

Car cranks but won't start

The engine turns over normally and never catches. The battery and starter are doing their jobs, so the engine is missing fuel, spark, or permission to run. Check the obvious thing first: the fuel gauge. Gauges do stick, and running out of gas happens more than anyone admits. After that it's the fuel pump, the ignition, or the immobilizer. If a key or padlock symbol is lit on the dash, the car doesn't recognize the key, and more cranking won't change its mind.

It starts for a second or two, then dies

The engine can fire but can't keep running. Fuel delivery, a vacuum leak, or the immobilizer cutting the engine just after it catches. You won't fix this one at the roadside, but it helps to know it isn't the battery, so nobody sells you one.

Nothing happens and the car is an automatic

Put it firmly in Park and try again. Then try Neutral. If it starts in Neutral but not in Park, the neutral safety switch is the problem and the engine is fine. It takes ten seconds and saves a tow often enough to be worth trying every time.

Four things to check before you call anyone

1. The key fob battery, if you have push-button start. A dead fob can look exactly like a dead car. Many fobs will still work if you hold them against the start button; your owner's manual shows where.
2. The steering lock. If the key won't turn at all, rock the steering wheel left and right while turning the key gently. The lock pin binds against the column and holds the ignition.
3. The gear selector, as above.
4. The battery terminals. Loose or corroded terminals are visible without any tools.

When a jump start won't help

A jump start fixes one thing: a battery without enough charge. If the car makes a single click, cranks strongly without firing, or starts and dies, jumping it will do nothing, and you'll have spent twenty minutes finding that out. Match the sound first.

If a jump does work, take it as a clue rather than a repair. What you need to know is whether the charging system is topping the battery back up, and any mechanic can test that in your driveway in a few minutes with a multimeter.

Why it's worth two minutes

You're probably not going to fix the car yourself. The point of the triage is that it changes who you call and what you tell them. "It clicks fast and the lights are dim" and "it cranks but won't catch" send two different people with two different parts. Getting that one sentence right is often what gets the car moving today instead of on Thursday.