Jump Start a Car

Use jumper cables and a running donor vehicle, or a portable jump pack, to start a car with a weak 12V battery by connecting power in the correct order and following strict safety precautions.

Medium · 10-20 minutes

Tools

  • Jumper cables or a portable jump starter
  • Safety glasses

Safety

  • Read both vehicles’ owner manuals first, especially for battery location, jump points, and any restrictions.
  • Only jump-start compatible 12V systems unless the manufacturer specifically allows otherwise.
  • Do not attempt this if the battery is cracked, leaking, swollen, badly corroded, or frozen.
  • Keep flames, cigarettes, and sparks away from the battery area.
  • Turn both vehicles off, set parking brakes, and put transmissions in Park or Neutral.
  • Remove keys or keep key fobs away from the ignition area before connecting cables.
  • Connect cables in the correct order: positive to dead battery, positive to donor battery, negative to donor battery, then negative to an unpainted metal ground on the disabled vehicle.
  • Do not connect the final negative clamp directly to the dead battery unless the manual specifically instructs it.
  • Keep clamps from touching each other, and keep cables clear of fans, belts, and other moving parts.
  • Wear eye protection and avoid leaning directly over the battery.
  • If either vehicle is hybrid, electric, or has a start-stop system, follow the manual exactly or use professional roadside service.
  • If the car does not start after a few attempts, stop and call a professional.

Steps

  1. Step 1: Prepare both vehicles

    • Park the donor vehicle close enough for the cables to reach, but make sure the vehicles do not touch.
    • Turn off both vehicles.
    • Set both parking brakes and place each transmission in Park or Neutral.
    • Open the hoods and locate the batteries or designated jump-start terminals.
    • Identify the positive (+) and negative (-) terminals on both vehicles.

    Check: Both vehicles are off and secured. · You can clearly identify positive and negative terminals or designated jump points. · The battery is not cracked, leaking, swollen, frozen, or otherwise damaged.

  2. Step 2: Connect the positive cable

    • Take the red positive jumper cable clamp and connect it to the positive (+) terminal of the dead battery.
    • Connect the other red positive clamp to the positive (+) terminal of the donor battery.

    Check: Both red clamps are firmly attached to positive terminals. · The clamps are not loose and are not touching any metal other than the intended terminals.

  3. Step 3: Connect the negative cable

    • Connect the black negative clamp to the negative (-) terminal of the donor battery.
    • Connect the remaining black clamp to a clean, unpainted metal ground point on the disabled vehicle, away from the battery if possible.

    Check: The final black clamp is attached to a solid metal ground on the disabled vehicle. · No clamps are touching each other. · The cables are routed away from belts, fans, and other moving parts.

  4. Step 4: Start the donor vehicle and wait briefly

    • Start the donor vehicle.
    • Let it run for 2 to 5 minutes to send some charge to the dead battery.

    Check: The donor vehicle is running smoothly. · The cables remain secure and clear of moving parts.

  5. Step 5: Try to start the disabled vehicle

    • Attempt to start the disabled vehicle.
    • If it does not start, wait another few minutes and try again.
    • Do not crank for long periods; use short attempts.

    Check: The disabled vehicle starts, or you stop after a few reasonable attempts. · There is no smoke, strong burning smell, or sparking beyond a small initial connection spark.

  6. Step 6: Disconnect the cables in reverse order

    • Once the disabled vehicle starts, remove the black clamp from the grounded metal point on the disabled vehicle.
    • Remove the black clamp from the donor battery negative terminal.
    • Remove the red clamp from the donor battery positive terminal.
    • Remove the red clamp from the revived vehicle positive terminal.

    Check: The clamps are removed in reverse order. · The clamps do not touch each other during removal. · Both vehicles remain clear of loose cables.

  7. Step 7: Let the revived vehicle run

    • Keep the revived vehicle running for at least 15 to 30 minutes, or drive it if safe to do so, to help recharge the battery.
    • If the battery dies again soon after, have the battery and charging system tested.

    Check: The vehicle continues running after cable removal. · Warning lights, dim lights, or repeated no-start symptoms are noted for follow-up.

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auto

Jump Start a Car

Medium10-20 minutes

Use jumper cables and a running donor vehicle, or a portable jump pack, to start a car with a weak 12V battery by connecting power in the correct order and following strict safety precautions.

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⚡Safety Warning
  • Read both vehicles’ owner manuals first, especially for battery location, jump points, and any restrictions.
  • Only jump-start compatible 12V systems unless the manufacturer specifically allows otherwise.
  • Do not attempt this if the battery is cracked, leaking, swollen, badly corroded, or frozen.
  • Keep flames, cigarettes, and sparks away from the battery area.
  • Turn both vehicles off, set parking brakes, and put transmissions in Park or Neutral.
  • Remove keys or keep key fobs away from the ignition area before connecting cables.
  • Connect cables in the correct order: positive to dead battery, positive to donor battery, negative to donor battery, then negative to an unpainted metal ground on the disabled vehicle.
  • Do not connect the final negative clamp directly to the dead battery unless the manual specifically instructs it.
  • Keep clamps from touching each other, and keep cables clear of fans, belts, and other moving parts.
  • Wear eye protection and avoid leaning directly over the battery.
  • If either vehicle is hybrid, electric, or has a start-stop system, follow the manual exactly or use professional roadside service.
  • If the car does not start after a few attempts, stop and call a professional.

Tools & Materials

  • Jumper cables or a portable jump starter
  • Safety glasses

Step-by-Step Instructions

Step 1

Prepare both vehicles

Diagram for step 1: Prepare both vehicles
  • Park the donor vehicle close enough for the cables to reach, but make sure the vehicles do not touch.
  • Turn off both vehicles.
  • Set both parking brakes and place each transmission in Park or Neutral.
  • Open the hoods and locate the batteries or designated jump-start terminals.
  • Identify the positive (+) and negative (-) terminals on both vehicles.
Check

Both vehicles are off and secured. • You can clearly identify positive and negative terminals or designated jump points. • The battery is not cracked, leaking, swollen, frozen, or otherwise damaged.

Was this step clear?
Step 2

Connect the positive cable

Diagram for step 2: Connect the positive cable
  • Take the red positive jumper cable clamp and connect it to the positive (+) terminal of the dead battery.
  • Connect the other red positive clamp to the positive (+) terminal of the donor battery.
Check

Both red clamps are firmly attached to positive terminals. • The clamps are not loose and are not touching any metal other than the intended terminals.

Was this step clear?
Step 3

Connect the negative cable

Diagram for step 3: Connect the negative cable
  • Connect the black negative clamp to the negative (-) terminal of the donor battery.
  • Connect the remaining black clamp to a clean, unpainted metal ground point on the disabled vehicle, away from the battery if possible.
Check

The final black clamp is attached to a solid metal ground on the disabled vehicle. • No clamps are touching each other. • The cables are routed away from belts, fans, and other moving parts.

Was this step clear?
Step 4

Start the donor vehicle and wait briefly

Diagram for step 4: Start the donor vehicle and wait briefly
  • Start the donor vehicle.
  • Let it run for 2 to 5 minutes to send some charge to the dead battery.
Check

The donor vehicle is running smoothly. • The cables remain secure and clear of moving parts.

Was this step clear?
Step 5

Try to start the disabled vehicle

Diagram for step 5: Try to start the disabled vehicle
  • Attempt to start the disabled vehicle.
  • If it does not start, wait another few minutes and try again.
  • Do not crank for long periods; use short attempts.
Check

The disabled vehicle starts, or you stop after a few reasonable attempts. • There is no smoke, strong burning smell, or sparking beyond a small initial connection spark.

Was this step clear?
Step 6

Disconnect the cables in reverse order

Diagram for step 6: Disconnect the cables in reverse order
  • Once the disabled vehicle starts, remove the black clamp from the grounded metal point on the disabled vehicle.
  • Remove the black clamp from the donor battery negative terminal.
  • Remove the red clamp from the donor battery positive terminal.
  • Remove the red clamp from the revived vehicle positive terminal.
Check

The clamps are removed in reverse order. • The clamps do not touch each other during removal. • Both vehicles remain clear of loose cables.

Was this step clear?
Step 7

Let the revived vehicle run

Diagram for step 7: Let the revived vehicle run
  • Keep the revived vehicle running for at least 15 to 30 minutes, or drive it if safe to do so, to help recharge the battery.
  • If the battery dies again soon after, have the battery and charging system tested.
Check

The vehicle continues running after cable removal. • Warning lights, dim lights, or repeated no-start symptoms are noted for follow-up.

Was this step clear?

Common Mistakes

  • ×Connecting the cables in the wrong order or reversing polarity.
  • ×Attaching the final negative clamp directly to the dead battery instead of a proper ground point when the manual says to use a ground.
  • ×Trying to jump-start a damaged, leaking, swollen, or frozen battery.
  • ×Letting the cable clamps touch each other.
  • ×Placing cables near fans or belts.
  • ×Cranking the dead vehicle repeatedly for too long.
  • ×Assuming all modern, hybrid, or start-stop vehicles should be jumped the same way.

When to Call a Professional

  • The battery is cracked, leaking, swollen, heavily corroded, or frozen.
  • You cannot clearly identify the correct jump points or battery polarity.
  • The vehicle is hybrid, electric, or has special manufacturer jump-start procedures you cannot confirm.
  • The car does not start after a few short attempts.
  • You notice smoke, heat, a strong sulfur smell, or unusual sparking.
  • The vehicle starts but immediately dies again, or electrical systems behave abnormally.

Notes

  • A portable jump starter can be safer and simpler than using another vehicle if used according to its instructions.
  • Some vehicles have remote positive and negative jump points instead of exposed battery terminals.
  • After a successful jump, the battery may still need charging, testing, or replacement.
  • A dead battery can be a symptom of another issue, such as a failing alternator, loose terminals, or a parasitic drain.

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