Car won’t start: battery, starter or alternator?

What the sound tells you, what to try, and when it’s a jump-start versus a tow.

Updated

A flat battery is the usual reason a car won’t start. Heat, short stop-start trips and days parked all drain batteries. But the sound the car makes when you turn the key tells you a lot.

What you hear, and what it usually means

Rapid clicking, dashboard lights dim or flicker. The battery has some charge but not enough to turn the engine. A jump-start usually works.

Nothing at all, no lights. The battery is completely flat, or a terminal is loose or corroded. Check that the clamps on the battery posts are tight. If they are, it needs a jump.

The engine cranks normally but doesn’t catch. The battery is fine. The problem is fuel or ignition. Check the fuel gauge first. If there’s fuel, it needs a mechanic, and a tow.

One loud click, then nothing, with full dashboard lights. Often the starter motor. A jump won’t help. It needs a tow to your mechanic.

After a jump-start

If the car starts on a jump, keep it running and drive for at least 30 minutes so the alternator can recharge the battery. Avoid switching it off at the first stop.

If it dies again within a day, one of two things is likely:

  • The battery can’t hold a charge. Batteries typically last two to four years in Philippine heat.
  • The alternator isn’t charging. Warning signs are a battery light on the dashboard while driving, and lights that dim at idle.

A battery shop or mechanic can test both the battery and the alternator to tell you which one it is.

Automatic cars can’t be push-started

The old trick of pushing the car and popping the clutch only works on manuals. Don’t try it with an automatic. It won’t work and can damage the transmission.