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Difficulty: Moderately Easy

Knowing how to jump-start a car with a dead battery can keep
an inconvenience from becoming a crisis. If you are unsure
about how to use jumper cables, ask for help.

Steps

1. Read your owner's manual, as it will describe any peculiarities involved in jump-starting your vehicle.
2. Pull a car with a charged battery next to the car with the dead battery, situating the two batteries as close together as you can without allowing the two cars to touch.

3. Turn off both engines, pull out the keys, put both cars in park (or in first gear if they have stick shifts), engage the emergency brakes and open the hoods.
4. Attach a red-handled/positive jumper cable clamp to the positive terminal (the one with the plus sign) of the charged battery.

5. Connect the other red-handled clamp to the positive terminal of the dead battery.

6. Attach the neighboring black/negative cable to the car with the dead battery. Clamp it somewhere where the current can ground out, such as a bolt or bracket on the engine. You can also attach it to any metal, unpainted part of the vehicle's frame.

7. Ground the other black/negative cable on the charging car, as described in the previous step. Be careful, as a small spark may be produced.
8. Attempt to start the car that has the dead battery.
9. Re-adjust the red/positive clamp on the dead car if there is no response; try reclamping it to the terminal or turning it for a better connection. Keep trying to start the dead car.
10. Once the dead car is running, remove the clamps one at a time in reverse order.
11. Allow the jump-started car to run for half an hour in order to charge the battery. It will charge whether driving or idling.

Tips & Warnings

• Always check your owners manual before jump-starting a car. Some new cars have special 'jump-start lugs' where jumper cables are attached rather than to the battery cables. These allow the potentially damaging surge of current to bypass the electrical system (and all those fancy, new onboard computers).
• If the dead car won't respond, there might be a problem in another part of the ignition system. Consult a mechanic.
• After you jump-start a dead car, run the engine for half an hour to charge the battery.
• Avoid starting or running the charged car while jump-starting the dead one. This is a common mistake in jump-starting cars. This can release a power surge into the charging car and blow a fuse, damage the alternator, or harm other areas of the electrical system.
• Many early British cars, such as Jaguars and MGs, use a positive ground instead of the popular negative ground. Consult a mechanic if you're in doubt about how to jump-start your particular car.
• The voltage from a car battery is dangerous whether the engine is running or not. Do not touch the metal ends of the jumper cables with your hands, nor touch them to each other. Never grasp both battery terminals at the same time.

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