OILCHANGEDIY
Guide

How to Jump-Start a Car (Safely)

The correct cable order, safety precautions, and what to do once the engine is running again.

Reviewed by Michael Koster · Updated April 2026

1. Before you connect anything

  • Park the working (donor) car close to the dead one, but make sure the two vehicles are not touching.
  • Put both cars in Park (or Neutral for a manual), set the parking brakes, and turn off the ignition on both.
  • Inspect the dead battery — if it’s cracked, leaking, or visibly bulging, do not jump it. Call for help.

2. Connect the cables in the right order

  • Connect a red clamp to the positive (+) terminal of the dead battery.
  • Connect the other red clamp to the positive (+) terminal of the good battery.
  • Connect a black clamp to the negative (−) terminal of the good battery.
  • Connect the last black clamp to a bare, unpainted metal bolt or bracket on the dead car’s engine block — not the dead battery. This reduces spark risk near battery gases.

3. Start the engines

  • Start the working car and let it run for 2–3 minutes to feed some charge into the dead battery.
  • Try to start the dead car. If it doesn’t catch, wait a few minutes and try again.
  • If it still won’t start after several tries, the battery may be fully dead or the problem is elsewhere.

4. Disconnect and keep it running

  • Remove the cables in reverse order: black from the engine block, black from the good battery, red from the good battery, red from the revived battery.
  • Keep the revived car running and drive it for at least 20–30 minutes so the alternator can recharge the battery.
  • If the car won’t restart later, the battery likely needs replacing or charging — have it tested at a parts store.
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