How to Jump-Start a Car Safely, Step by Step

Before you start

• Check your owner's manual first — some vehicles have remote jump-start terminals under the hood, and the procedure can vary by make.
• Park the two vehicles close but not touching. Both in Park (or Neutral), parking brakes on, ignitions off, lights and accessories off.
• Keep cables away from fans, belts and other moving parts.
• Never let the metal clamps touch each other once any clamp is connected.

Don't jump a frozen or damaged battery

In a Northland cold snap, look at the battery before you hook up. If the case is swollen, bulging, cracked or leaking, do not connect cables. A frozen battery can crack and spray acid. Call for help instead.

Connect the cables in this order

• 1. Red (+) clamp to the dead battery's positive terminal.
• 2. Other red (+) clamp to the good battery's positive terminal.
• 3. Black (−) clamp to the good battery's negative terminal.
• 4. Last black (−) clamp to bare, unpainted metal on the dead car's engine or frame — several inches away from the battery. Not on the dead battery's negative post.

That last connection is made away from the battery on purpose: batteries can give off flammable gas, and the final connection is where a spark is most likely.

Start it up

• Start the good car and let it run a few minutes.
• Try starting the dead car. If it doesn't catch, let the good car run a bit longer and try again.
• Once it starts, remove the cables in the reverse order: the black clamp on the engine metal first, then black on the good car, then red on the good car, then red on the formerly dead car.
• Drive for at least 20–30 minutes so the alternator can put some charge back in.

If it keeps dying

A battery that needs a jump again and again is telling you something. It may be worn out — especially if it's more than about three years old — or the alternator or starter may be the real problem. We test the battery and charging system on site and can replace what's actually failing.