How to Jump-Start a Car: The Correct Order to Attach and Remove Jumper Cables

Connect the cables in this order: 1) red clamp to the dead battery’s positive (+), 2) red clamp to the donor battery’s positive (+), 3) black clamp to the donor battery’s negative (−), 4) black clamp to an unpainted metal ground on the dead car (or its designated negative jump point). Start the donor, wait a few minutes, then start the dead car. Disconnect in reverse order. This sequence minimizes sparks near the battery and protects electronics.

Before You Begin: Safety and Quick Checks

Before connecting anything, confirm both vehicles use the same system (typically 12V), inspect the battery for damage, and set up a safe work area. These steps reduce the risk of injury, battery damage, or electrical system harm.

• Verify both vehicles are 12V systems; never jump 12V from a 24V truck or vice versa.
• Check the dead battery for cracks, bulges, leaks, or strong rotten-egg smell (hydrogen sulfide). If present, do not jump—replace the battery.
• Ensure batteries aren’t frozen. A frozen battery can explode when charged.
• Turn off both ignitions and all accessories; set parking brakes; place transmissions in Park (automatic) or Neutral (manual).
• Keep vehicles from touching; remove metal jewelry; wear eye protection.
• Locate the designated jump-start posts if your car has them (common on many modern, hybrid, or stop-start vehicles).
• Use quality, undamaged cables (4–6 gauge is ideal for most cars) or a reputable jump pack.

With these checks complete, you can connect the cables confidently and safely.

The Correct Order to Connect Jumper Cables

Follow this exact connection order to reduce spark risk and protect sensitive electronics.

1. Attach the red (positive) clamp to the positive (+) terminal of the dead battery or its positive jump post.
2. Attach the other red (positive) clamp to the positive (+) terminal of the donor battery.
3. Attach the black (negative) clamp to the negative (−) terminal of the donor battery.
4. Attach the other black (negative) clamp to a clean, unpainted metal ground on the dead car (such as a solid engine or chassis point) or the manufacturer’s designated negative post—never near the battery vent.

This sequence keeps any arcing away from the dead battery, where hydrogen gas may be present, and aligns with most manufacturer recommendations.

Starting Sequence

After connecting, bring power to the dead battery gradually, then attempt a start. Adjust timing based on how depleted the battery is.

1. Start the donor vehicle and let it run for 2–5 minutes at a low idle (up to ~1,500–2,000 RPM if needed).
2. Try starting the dead vehicle. If it doesn’t crank, wait another 2–3 minutes and try again.
3. If the dead car starts, let both vehicles idle connected for another 1–2 minutes to stabilize voltage.

If the dead car still won’t start after several attempts, stop and troubleshoot rather than repeatedly cranking, which can overheat cables and starters.

The Correct Order to Disconnect Jumper Cables

Remove the clamps in reverse order to safely break the circuit and avoid accidental shorting.

1. Remove the black (negative) clamp from the dead car’s ground point or negative jump post.
2. Remove the black (negative) clamp from the donor battery’s negative (−) terminal.
3. Remove the red (positive) clamp from the donor battery’s positive (+) terminal.
4. Remove the red (positive) clamp from the dead battery’s positive (+) terminal.

Keep the metal clamps from touching any metal or each other during removal to prevent sparks.

If You’re Using a Portable Jump Starter

Portable jump packs simplify the process and isolate your vehicle from another car’s alternator and electronics.

1. Power off the jump pack and confirm it’s charged.
2. Connect the red clamp to the dead battery’s positive (+) terminal or positive jump post.
3. Connect the black clamp to the vehicle’s designated negative post or a solid, unpainted metal ground.
4. Power on the jump pack and attempt to start the vehicle.
5. Once started, power off the pack and remove the clamps in reverse order (black off first, then red).

Consult your jump pack’s manual for any built-in safety or boost modes and follow its specific instructions.

Special Cases and Warnings

Some vehicles have unique requirements or risks. Check your owner’s manual if you’re unsure.

• Hybrids/EVs: Do not attempt to jump the high-voltage system. You may use the 12V posts if the manual permits. Many EVs can be jump-started only to wake the 12V system.
• Stop-start and AGM/EFB batteries: Use the designated under-hood jump points; avoid clamping directly onto battery sensors or modules.
• 48V mild hybrids: Never cross 48V systems with 12V jump cables. Use manufacturer-approved jump points.
• Donor engine running or off: Most makers allow the donor to run at idle to supply current. Some advise engine off to reduce surge risk—follow your manual.
• Battery management sensors: Many modern cars have a sensor on the negative terminal—use the specified ground/jump point instead of clamping on the sensor.
• Do not jump a swollen, leaking, or frozen battery. Replace it safely.
• Voltage mismatch: Never jump between 6V/12V/24V systems.

When in doubt, use a quality jump pack or call roadside assistance to avoid costly electrical damage.

Troubleshooting If It Won’t Start

If the car still refuses to start, a deeper issue may be present. Use these checks to narrow it down.

• Connections: Ensure clamps bite clean metal and aren’t on paint or corrosion.
• Wait longer: Severely discharged batteries may need 5–10 minutes of donor idle before cranking.
• Cable quality: Thin or damaged cables can’t carry enough current.
• Battery failure: A battery older than ~4–5 years may be beyond recovery; test or replace it.
• Starter/ignition issues: If lights work but the engine won’t crank, the starter or immobilizer may be at fault.
• Clicking only: Often a sign of low voltage or poor ground; recheck the ground point.
• Repeated failure: Consider a parasitic drain or alternator problem; have the charging system tested.

A quick battery and charging-system test at an auto parts store or with a multimeter can confirm the diagnosis.

After the Jump: What to Do Next

Once your car is running, give the alternator time to recharge the battery and prevent another no-start.

• Keep the engine running for at least 20–30 minutes; a steady drive is better than idling.
• Avoid heavy electrical loads (rear defroster, heated seats) while recharging.
• If the battery dies again soon, schedule a load test and alternator/parasite-draw check.
• Clean and tighten battery terminals; consider replacing an aging battery.

Proactive checks after a jump reduce repeat failures and protect your vehicle’s electronics.

Summary

Attach cables in this order: red to dead (+), red to donor (+), black to donor (−), black to a solid ground on the dead car—then start the donor, wait a few minutes, and start the dead car. Disconnect in reverse. Use designated jump points on modern vehicles, avoid sparks near the battery, and confirm matching voltages. If problems persist, test the battery and charging system or use a portable jump starter for a safer, simpler boost.

In what order should I jump start?

To jump-start a car, the jumper cable connection order is crucial for safety. Connect the red clamp to the positive terminal of the dead battery first, then the other red clamp to the positive terminal of the working (donor) battery. Next, connect the black clamp to the negative terminal of the working battery, and finally, connect the other black clamp to an unpainted metal surface on the dead car’s engine block away from the battery. Disconnect the cables in the reverse order.
 
Connecting the Jumper Cables

1. Red to Dead Battery: Connect the red (positive) clamp of the jumper cable to the positive terminal (+) of the car with the dead battery. 
2. Red to Donor Battery: Connect the other red (positive) clamp to the positive terminal (+) of the car with the working battery. 
3. Black to Donor Battery: Connect the black (negative) clamp to the negative terminal (-) of the car with the working battery. 
4. Black to Ground: Connect the final black (negative) clamp to an unpainted metal surface on the engine block of the car with the dead battery, away from the battery itself. 

Starting and Disconnecting

1. Start the Working Car: Start the engine of the vehicle with the good (donor) battery and let it run for a few minutes. 
2. Start the Dead Car: Try to start the engine of the car with the dead battery. 
3. Disconnect in Reverse Order: Once the dead car’s engine is running, disconnect the cables in the following reverse order: 
   • Black clamp from the engine block. 
   • Black clamp from the donor vehicle’s negative terminal. 
   • Red clamp from the donor vehicle’s positive terminal. 
   • Red clamp from the dead battery. 

This video demonstrates the proper way to jump start a car: 58sAAA Connect Video Hub | Auto Club GroupYouTube · Sep 23, 2024
Important Safety Tips

• Ensure both cars are turned off and the parking brakes are engaged. 
• Make sure the cars are close enough to reach but not touching. 
• Avoid contact between the positive and negative cables to prevent sparks. 
• If the dead car doesn’t start after a few tries, there may be a more serious issue requiring a mechanic. 

What is the proper order for jumping a car?

To jump a car battery, connect jumper cables by first attaching the red clamp to the dead battery’s positive (+) terminal, then the other red clamp to the working car’s positive terminal. Next, connect the black clamp to the working car’s negative (-) terminal and the final black clamp to an unpainted metal surface on the dead car, away from the battery. After connecting both cars, start the working vehicle to charge the dead battery, then try to start the dead car.
 
This video demonstrates the complete process of jump-starting a car, including safety precautions: 50sCars.comYouTube · Oct 11, 2024
Step-by-Step Connection Guide:

1. Position the vehicles: Park the working car close to the dead car, but ensure they do not touch. 
2. Turn off both cars: Make sure both vehicles are completely off before connecting anything. 
3. Locate battery terminals: Identify the positive (+) and negative (-) terminals on each battery. 
4. Connect the red (positive) cables: 
   • Attach one red clamp to the dead battery’s positive (+) terminal. 
   • Attach the other red clamp to the working battery’s positive (+) terminal. 
5. Connect the black (negative) cables: 
   • Attach one black clamp to the working battery’s negative (-) terminal. 
   • Attach the final black clamp to an unpainted, unmoving metal part of the dead car (like the engine block). This helps prevent sparks near the battery. 
6. Start the working car: Let the working car run for a few minutes to begin charging the dead battery. 
7. Start the dead car: Attempt to start the dead car. 
8. Disconnect the cables: Once the dead car starts, disconnect the jumper cables in the reverse order: black negative clamp from the dead car’s metal surface, then the black negative clamp from the working car, then the red positive clamp from the working car, and finally the red positive clamp from the dead battery. 

This video shows the step-by-step process of disconnecting the cables after a successful jump-start: 58sAAA Connect Video Hub | Auto Club GroupYouTube · Sep 23, 2024
Why the Order Matters:
The correct order is crucial for safety. Connecting the last negative clamp to a grounded metal surface helps prevent sparks, which can be a fire or explosion hazard with lead-acid batteries, especially if they are venting hydrogen gas. 
After the Jump:
Let the jump-started car run for at least 15-20 minutes to allow the alternator to fully charge the battery.

Is there an order for putting on jumper cables?

Make sure you have followed these steps in proper order: red clip from booster cable to positive terminals, then black clip from booster cable to negative terminals. Once all connections are made, start up your working vehicle and let it run for a few minutes before attempting to start your dead battery’s engine.

What are the 5 steps to jumpstart a car?

How to Use Jumper Cables to Start a Car

1. Step 1: Park the Cars Safely.
2. Step 2: Turn Both Cars Off.
3. Step 3: Find the Battery Terminals.
4. Step 4: Connect the Red Jumper Cable Clamps.
5. Step 5: Connect the Black Jumper Cable Clamps.
6. Step 6: Jump-Start the Car.
7. Step 7: Disconnect the Black Cable Clamps.