Car Won't Start on a Cold, Wet Morning? What to Check First

A car that will not start is stressful, but the symptoms narrow the problem down quickly. Before you do anything else, notice exactly what happens when you turn the key or push the button.

What the sound is telling you

• Rapid clicking: the battery is too weak to turn the starter, or the connections are poor. This is the classic dead-battery sound.
• A single loud click: could be a very weak battery, a bad connection, or the starter itself.
• Slow, labouring crank: the battery is weak and struggling, especially common on cold mornings.
• Nothing at all, with dim or dead dash lights: a very flat battery or loose, corroded terminals.
• Engine cranks normally but will not catch: this is usually fuel or ignition, not the battery.

Quick checks you can do safely

1. Turn on the headlights. If they are bright but the car only clicks, the problem is more likely the starter or a connection. If they are dim or off, the battery is probably flat.
2. Look at the terminals for white or green crust and see whether the cable ends are tight. Do not touch anything if you are unsure.
3. Try the spare key or hold the key fob against the start button. A weak fob battery can stop some cars from starting.
4. Do not keep cranking. Ten seconds at a time, then wait a minute. Repeated cranking drains whatever is left.

Why cold and damp make it worse

A cold battery delivers less power, while cold engine oil is thicker and makes the engine harder to turn. Damp air also speeds corrosion on the terminals. A battery that was just good enough in September can be not good enough on the first cold morning of the season.

When to call

If the car clicks or cranks slowly and the battery is more than three or four years old, the battery is the most likely cause. A mobile technician can test it where it is parked and replace it on the spot if it is done.