The Proper Order to Attach Jumper Cables

Attach cables in this order: red to the dead battery’s positive (+), red to the good battery’s positive (+), black to the good battery’s negative (−), black to an unpainted metal ground on the dead car; then remove the cables in the reverse order after the dead car starts. This sequence minimizes sparks near the battery and protects sensitive electronics in modern vehicles. Below is a practical, safety-focused guide to jump-starting with the correct order, plus tips for today’s cars, trucks, hybrids, and EVs.

Why the Order Matters

The connection sequence is designed to keep sparks away from the dead battery, where explosive gases may be present, and to stabilize voltage between both vehicles. Using a solid engine or chassis ground on the disabled vehicle for the final clamp reduces ignition risk and helps ensure a clean electrical path.

Step-by-Step: Attaching the Cables

Follow these steps when both vehicles are in Park (or Neutral for manual), with ignitions off, parking brakes on, and lights and accessories switched off. If your vehicle has remote jump-start posts, use those instead of the battery terminals.

1. Red to dead: Attach the red (positive) clamp to the positive (+) terminal on the dead car’s battery or designated positive post.
2. Red to good: Attach the other red clamp to the positive (+) terminal on the good (donor) battery or its designated positive post.
3. Black to good: Attach the black (negative) clamp to the donor car’s negative (−) terminal or designated negative post.
4. Black to ground on dead car: Attach the final black clamp to a clean, unpainted metal part on the dead car—such as an engine lifting eye, a solid bracket, or a designated ground point—well away from the battery and moving parts.

This order limits the chance of short circuits and keeps the final spark away from the dead battery area. If the dead car has a labeled ground/jump point, use that instead of the engine block.

Starting Procedure

Once connected, you’ll need to safely bring the dead battery up enough to crank the engine. These steps help charge and start the vehicle without over-stressing components.

1. Start the donor car and let it idle for 2–5 minutes; gently raise RPM to 1,500–2,000 if the cables are light-duty or the dead battery is very weak.
2. Try starting the dead car. If it doesn’t crank, wait another 2–3 minutes and try again. Avoid repeated rapid cranks—give the starter time to cool.
3. Once the dead car starts, keep both vehicles running for a minute or two to stabilize voltage.

Patience here prevents overheating the donor alternator and gives the dead battery a short boost before the first crank.

Removing the Cables (Reverse Order)

Disconnecting in the reverse order prevents accidental contact between live clamps and reduces spark risk as you separate the circuit.

1. Remove the black clamp from the grounded metal point on the previously dead car.
2. Remove the black clamp from the donor car’s negative (−) terminal.
3. Remove the red clamp from the donor car’s positive (+) terminal.
4. Remove the red clamp from the previously dead car’s positive (+) terminal.

Keep the free clamps from touching each other or metal parts as you remove them, and stow the cables safely once done.

Aftercare: Let It Recharge

After a successful jump, the formerly dead vehicle’s alternator needs time to replenish the battery.

• Drive for at least 20–30 minutes at road speeds, avoiding heavy electrical loads (heated seats, rear defrost) if possible.
• If the engine stalls or won’t hold idle, seek service—your battery or charging system may be failing.

This brief recharge period helps restore surface charge and can prevent another no-start the next time you shut off the engine.

Common Mistakes to Avoid

These pitfalls can damage electronics, create sparks, or leave you stranded.

• Do not connect the final black clamp to the dead battery’s negative terminal—use a ground on the dead car.
• Do not let clamps touch each other or the wrong terminals (red to red, black to ground only).
• Avoid loose, corroded, or painted contact points; ensure solid metal contact.
• Don’t crank continuously—limit attempts to about 10 seconds, then rest 30–60 seconds.
• Avoid cheap, thin cables for trucks/SUVs; heavier 4- or 2‑gauge cables work better.

Sticking to proper connection points and quality cables dramatically improves safety and success rates.

Special Cases: Modern Cars, Hybrids, and EVs

Many newer vehicles include battery management systems or remote jump posts, and hybrids/EVs use 12V batteries differently. Review these considerations before you connect.

• Remote posts: Use the under-hood positive post and designated ground if provided; access to the battery itself may be restricted.
• Start-stop/AGM/EFB batteries: The jump procedure is the same, but these batteries are more sensitive. If issues persist, test and register replacements as required by the vehicle.
• Lithium 12V batteries (rare in mainstream cars): Check the owner’s manual for jump-start restrictions to avoid BMS shutdown or damage.
• Hybrids: You’re jump-starting the 12V system only. Use the specified posts; do not access high-voltage components.
• EVs as donors: Many manufacturers advise against using an EV to jump another vehicle. However, most EVs can be jump-started themselves via their 12V posts with an external pack—follow the manual.

When in doubt, consult the owner’s manual for your exact vehicle; procedures and permitted connection points vary by brand and model year.

If It Still Won’t Start

If the vehicle doesn’t crank or start after several careful attempts, targeted checks can save time.

• Look for severe corrosion, loose clamps, or hidden terminal covers preventing good contact.
• Verify you have 12V power: dome lights, dash lights, or a volt reading of at least ~12.2V before cranking.
• Listen for a click (starter relay) or silence (possible dead battery or poor connection) vs. rapid clicking (very low voltage).
• Try a better ground point or heavier-gauge cables.
• Consider a truly dead or sulfated battery, blown main fuse, faulty starter, or alternator failure; professional testing may be required.

Persistent no-starts often indicate a failing battery or charging system rather than a cable issue alone.

Summary

Connect in this order: red to dead (+), red to good (+), black to good (−), black to ground on the dead car; remove in reverse. Use solid metal contact points, keep sparks away from the dead battery, and let the revived vehicle run to recharge. For modern vehicles, hybrids, and EVs, use the designated jump posts and follow the owner’s manual to protect sensitive systems.

What is the correct order to attach jumper cables?

It goes like. This red to the dead. Red to the good black to the good. Then under the hood. Now let’s watch as Brian from Henderson Auto puts all of that into action.

Do I connect black or red first?

When connecting jumper cables to a car with a dead battery, always connect the red/positive cable first to the positive (+) terminal of the dead battery, and then to the positive terminal of the working battery. The negative (black) cables should be connected last, with one to the negative terminal of the working battery and the other to an unpainted metal surface on the dead car’s engine block or frame to complete the circuit.
 
This video demonstrates how to safely connect jumper cables to a car battery: 51sStan CravensYouTube · Oct 9, 2018
Step-by-Step Guide to Connecting Jumper Cables:

1. Turn off both vehicles: Opens in new tabEnsure the ignition keys are in the off position in both the car with the dead battery and the donor car. 
2. Connect the red (positive) cable to the dead battery: Opens in new tabAttach one red clamp to the positive (+) terminal of the dead battery. 
3. Connect the red (positive) cable to the donor battery: Opens in new tabAttach the other red clamp to the positive (+) terminal of the good battery on the donor vehicle. 
4. Connect the black (negative) cable to the donor battery: Opens in new tabAttach one black clamp to the negative (-) terminal of the donor vehicle’s good battery. 
5. Connect the black (negative) cable to the dead car’s frame: Opens in new tabAttach the final black clamp to an unpainted, unmoving metal part of the engine block or frame of the car with the dead battery. A slight spark may occur, which is normal. 

Why this order?

• Red first: Connecting the positive (red) cable to both batteries first creates a complete circuit without completing the negative side. 
• Last connection to metal: The last black clamp is attached to an unpainted metal surface on the dead car’s frame, not the negative terminal. This minimizes the risk of sparks, as the battery releases hydrogen gas that could cause an explosion. 

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.

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.