How to jump-start a car

For anyone whose battery has died and who can borrow a second car, this returns power without damage or injury.

IJR · Sep 26, 2026 · 2 min read

0 merit0 reads

Connect the cables so every spark happens away from the dead battery. That order keeps fumes from igniting.

Have a set of jumper cables, a second car with a good twelve-volt battery, and both vehicles already in park.

1: PARK the two cars nose-to-nose or side-by-side eighteen inches apart so cables reach without the bodies touching. — **1: PARK** the two cars nose-to-nose or side-by-side eighteen inches apart so cables reach without the bodies touching.

Shut both engines off and pocket the keys. The gap works when you can step between the bumpers flat-footed. Roll one car back if metal is closer than a foot.

2: SET both parking brakes fully and switch off every light, radio, and accessory. — **2: SET** both parking brakes fully and switch off every light, radio, and accessory.

This stops either car from rolling once power returns. Push the pedal or pull the lever until it clicks solid. Hunt any remaining glow on the dash and kill that switch too.

3: CLIP the red clamp onto the dead-battery positive post marked plus, keeping the jaws clear of all other metal. — **3: CLIP** the red clamp onto the dead-battery positive post marked plus, keeping the jaws clear of all other metal.

Rock the clamp until it bites clean lead. A light tug leaves it fixed in place when the grip is right. Wire-brush any white crust before you clamp if the post looks furry.

4: CLIP the free red clamp onto the good-battery positive post marked plus. — **4: CLIP** the free red clamp onto the good-battery positive post marked plus.

Match the plus sign exactly. The jaws seat right when only bare metal sits inside them. Re-seat the clamp if it rocks on plastic housing.

5: CLIP the black clamp onto the good-battery negative post marked minus. — **5: CLIP** the black clamp onto the good-battery negative post marked minus.

Squeeze until the teeth lock. Firm spring tension tells you the connection is solid. Hold this black clamp away from every red clamp while you move.

6: CLIP the last black clamp onto bare unpainted metal on the dead-car engine block at least twelve inches from its battery. — **6: CLIP** the last black clamp onto bare unpainted metal on the dead-car engine block at least twelve inches from its battery.

Pick a clean nut or bracket far from fuel lines. Shiny metal under the teeth shows a true ground. Never use the dead-battery minus post itself.

7: START the good car and let it idle three full minutes before you touch the dead-car key. — **7: START** the good car and let it idle three full minutes before you touch the dead-car key.

Count sixty three times while it runs. Steady even revs mean the wait is done. Now turn the dead-car key; normal cranking sound means the jump took.

8: REMOVE the clamps in reverse order once the dead engine runs on its own. — **8: REMOVE** the clamps in reverse order once the dead engine runs on its own.

Black ground first, black off the good battery, red off the good battery, red off the dead battery last. You are done when both engines keep running free and the cables lie clear of all moving parts. Coil them loose so the metal ends cannot touch.

The most common mistake

Clamping the final black lead to the dead battery minus post creates sparks right at the cell. Always choose bare engine metal at least a foot away instead.

Pro tip

Leave both cars idling five more minutes after the dead one starts so its battery can accept a surface charge before you drive off.

Say it every time

red-dead red-good black-good black-metal

Comments

Free account · your comment posts right after signup

The most common mistake

Pro tip

Say it every time

Comments

Rankings the crowd is fighting over