Which jump cable goes first?

The first cable to attach is the red positive cable—connect it to the disabled vehicle’s positive (+) terminal or designated positive jump-start post. Then attach the other red clamp to the donor battery’s positive, followed by the black clamp to the donor battery’s negative (–), and finally the remaining black clamp to an unpainted metal ground on the disabled vehicle. This sequence reduces spark risk and follows current automotive safety guidance.

The correct connection order for car-to-car jump-starts

The sequence below reflects widely recommended procedures from roadside-assistance organizations and automakers, minimizing the chance of sparks near the battery and protecting modern vehicles’ battery sensors. Always consult your owner’s manual for vehicle-specific jump points and cautions.

1. Turn off both vehicles, remove keys, and set parking brakes; switch off all accessories (lights, HVAC, infotainment).
2. Connect the red (+) clamp to the disabled vehicle’s positive battery terminal or designated positive jump post.
3. Connect the other red (+) clamp to the donor vehicle’s positive battery terminal.
4. Connect the black (–) clamp to the donor vehicle’s negative battery terminal.
5. Connect the remaining black (–) clamp to a clean, unpainted metal ground on the disabled vehicle (such as a solid engine or chassis ground), away from the battery and moving parts.
6. Start the donor vehicle and let it run for 2–5 minutes, then attempt to start the disabled vehicle. If it doesn’t start, wait another few minutes and try again. Avoid cranking for more than 10 seconds at a time.

This order places the final connection away from the battery where explosive gases may be present, reducing ignition risk and protecting sensitive electronics common in 2010s–2020s vehicles.

Why red goes first—and why the last clamp goes to ground

Connecting positive first and making the final connection to a chassis ground keeps potential arcing away from the battery, which can vent hydrogen gas. Many modern cars also have a battery sensor (IBS) on the negative post; grounding to the chassis maintains proper current measurement and reduces the chance of damaging the sensor.

The safe disconnection order

Once the disabled vehicle is running, remove the cables in the reverse order to the way you connected them. This helps prevent accidental short circuits and sparks.

1. Remove the black (–) clamp from the disabled vehicle’s chassis ground.
2. Remove the black (–) clamp from the donor vehicle’s negative terminal.
3. Remove the red (+) clamp from the donor vehicle’s positive terminal.
4. Remove the red (+) clamp from the disabled vehicle’s positive terminal or jump post.

After disconnecting, keep the once-disabled vehicle running for at least 20–30 minutes or drive it to allow the alternator to recharge the battery, or have the battery tested if it repeatedly fails.

Using a portable jump starter (jump pack)

Portable lithium or lead-acid jump packs include built-in protections and are safer than car-to-car jumps in many situations. Follow the device’s manual, but the general steps are consistent with best practices.

1. Ensure the jump pack is at a sufficient state of charge (often above 75%). Power the pack off before connecting, if required by the manufacturer.
2. Connect the red (+) clamp to the disabled vehicle’s positive terminal or positive jump post.
3. Connect the black (–) clamp to a solid, unpainted chassis or engine ground on the disabled vehicle.
4. Power on the jump pack (or enable boost mode) and start the vehicle. Avoid repeated cranking; let cables cool if multiple attempts are needed.
5. Power off the jump pack, then remove the clamps in reverse: black ground first, then red positive.

Some jump packs offer reverse-polarity and spark protection, but you should still observe the same connection order to minimize risk.

Safety checks and exceptions

Before you connect anything, these checks can prevent injuries and vehicle damage. Some vehicles have exceptions or special procedures that must be followed.

• Inspect the battery: Do not jump if the battery is cracked, leaking, or frozen (a swollen case is a red flag).
• Use the designated jump posts if the battery is remote (trunk/under-seat) or covered; many 2015–2025 vehicles provide under-hood posts.
• Hybrid and electric vehicles: Never attempt to jump the high-voltage system. You may be able to jump or be jumped via the 12V battery posts per the manual; otherwise call roadside assistance.
• Stop-start and AGM/EFB batteries: Follow the owner’s manual; use the provided ground point to avoid damaging battery monitoring systems.
• Avoid contact between clamps and keep metal tools away from battery terminals to prevent short circuits.
• Wear eye protection and remove loose jewelry; ensure good ventilation around the battery area.
• If the disabled car cranks slowly after a few attempts, the battery may be beyond recovery or there may be a deeper charging-system fault.

Following these precautions aligns with guidance from major roadside services and automakers and reflects the needs of modern electrical systems.

Common mistakes to avoid

These errors are frequent causes of damage or injury during jump-start attempts and are easy to prevent with a quick double-check.

• Reversing polarity (black on positive, red on negative) or letting clamps touch while connected.
• Making the final connection to the dead battery post instead of a chassis ground.
• Jumping a visibly damaged, frozen, or excessively corroded battery.
• Revving the donor engine aggressively; a steady idle or light fast-idle is sufficient.
• Skipping the owner’s manual when vehicles have special jump-start terminals or restrictions.

A careful, step-by-step approach prevents most of these issues and ensures a safe, effective jump-start.

Summary

Attach the red positive cable first—preferably to the disabled vehicle’s positive terminal or marked jump post—then red to the donor positive, black to the donor negative, and finally black to an unpainted ground on the disabled vehicle. Disconnect in reverse. This procedure minimizes sparks, protects modern battery sensors, and aligns with current best practices for 12V automotive systems.

When using jumper cables, which goes on first?

When connecting jumper cables, you should attach the positive (red) cable to the dead battery first, then the positive cable to the good battery, followed by the negative cable to the good battery’s negative terminal, and finally, the negative cable to an unpainted metal surface on the car with the dead battery. This order helps prevent sparks that could ignite hydrogen gas from the battery.
 
Step-by-step connection process:

1. Position: the two vehicles close enough for the cables to reach, but not touching. 
2. Turn off: both vehicles and ensure they are in park. 
3. Attach: the red (positive) clamp to the positive (+) terminal of the dead battery. 
4. Attach: the other red (positive) clamp to the positive (+) terminal of the good (donor) battery. 
5. Attach: the black (negative) clamp to the negative (-) terminal of the good (donor) battery. 
6. Connect: the other black (negative) clamp to an unpainted, unmoving metal part of the dead car’s engine block or frame, away from the battery. 
7. Start: the engine of the working (donor) vehicle. 
8. Start: the engine of the car with the dead battery. 
9. Once started, remove the jumper cables in the reverse order: black from the dead car’s frame, black from the donor battery, red from the donor battery, and finally the red from the dead battery. 

This video demonstrates the correct order for connecting jumper cables: 1mKPTV FOX 12 | Local news, weather Portland, OregonYouTube · Oct 9, 2024
Why this order?
Attaching the positive terminals first completes one part of the circuit, but the final connection of the negative cable to a grounded metal surface away from the battery creates the full circuit. This is critical because batteries can release flammable hydrogen gas, and making the last connection on a grounded, unpainted metal part prevents a direct spark near the battery that could cause an explosion. 
You can watch this video to learn why this connection order is important for safety: 58sCNMsuncatsYouTube · Dec 5, 2024

What is the correct order of jumper cables?

To connect jumper cables correctly, attach the red (positive) clamps to the positive terminals of both batteries (dead first, then good), then attach the black (negative) clamps to the negative terminal of the good battery and an unpainted metal component (a “ground”) on the dead car. Remove them in the reverse order: first, the black clamp from the metal ground, then the black clamp from the good battery’s negative terminal, followed by the red clamps. 
Connecting the Cables

1. Red to Dead Battery (+): Opens in new tabConnect the first red clamp to the positive (+) terminal of the dead battery. 
2. Red to Good Battery (+): Opens in new tabConnect the other red clamp to the positive (+) terminal of the good battery in the working vehicle. 
3. Black to Good Battery (-): Opens in new tabConnect the first black clamp to the negative (-) terminal of the good battery. 
4. Black to Metal Ground: Opens in new tabConnect the final black clamp to an unpainted, non-moving metal component on the engine block or chassis of the vehicle with the dead battery. This avoids sparks near the battery, which can be a fire hazard due to gases it may release. 

This video demonstrates the entire process of connecting jumper cables, including the final grounding step: 56sLes SchwabYouTube · May 23, 2017
Starting the Vehicles

1. Start the Working Vehicle: Start the car with the good battery and let it run for several minutes to allow the battery to charge. 
2. Start the Stalled Vehicle: Attempt to start the car with the dead battery. 
3. Allow for Charging: If the car starts, let both vehicles run for at least 30 minutes to allow the alternator to fully charge the battery. 

Disconnecting the Cables (Reverse Order) 

1. Black from Metal Ground: Disconnect the black clamp from the unpainted metal component on the dead car. 
2. Black from Good Battery (-): Disconnect the black clamp from the negative terminal of the good battery. 
3. Red from Good Battery (+): Disconnect the red clamp from the positive terminal of the good battery. 
4. Red from Dead Battery (+): Disconnect the red clamp from the positive terminal of the dead 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 is the correct order to take off jumper cables?

To remove jumper cables safely, disconnect them in the reverse order of connection: first the negative (black) clamp from the dead car, then the negative (black) clamp from the good car, followed by the positive (red) clamp from the good car, and finally the positive (red) clamp from the dead car. This sequence prevents sparks and potential damage to your vehicles’ electrical systems.
 
This video demonstrates the entire process of jump-starting a car, including how to disconnect the jumper cables: 1mAmericas Drivers EdYouTube · Mar 31, 2016
Here are the steps for removing jumper cables safely:

1. Turn off both engines: to ensure no electrical current is flowing. 
2. Disconnect the black (negative) clamp: from the grounded metal on the car with the dead battery. 
3. Disconnect the black (negative) clamp: from the negative terminal of the good (jumping) car’s battery. 
4. Disconnect the red (positive) clamp: from the positive terminal of the good (jumping) car’s battery. 
5. Disconnect the red (positive) clamp: from the positive terminal of the formerly stalled car’s battery. 

Important Safety Tips:

• Maintain distance: Keep at least two feet of distance between the vehicles while disconnecting the cables to prevent accidental contact. 
• Avoid sparks: Removing the negative cables first helps to prevent a short circuit, which can cause sparks and potentially damage electrical components or even the battery. 
• Clip them together: When not connected to a terminal, it’s a good idea to clip the red and black ends of the cables together to keep them separated and avoid accidental contact.