How to Use Jumper Cables Step by Step

Attach the red clamp to the dead battery’s positive (+), the other red clamp to the donor battery’s positive (+), the black clamp to the donor battery’s negative (−), and the final black clamp to an unpainted metal ground on the dead car; start the donor, then start the dead car, and remove cables in reverse order. In practice, safe jump-starting means parking the vehicles correctly, verifying you’re working with 12-volt systems, using the proper connection points (often dedicated under-hood posts), and following a precise sequence to avoid sparks and damage to electronics.

Safety and Setup: What to Know Before You Begin

Jump-starting is straightforward but demands care. Modern vehicles often provide dedicated jump-start posts under the hood; using them is safer than clamping directly to battery terminals. Never jump a cracked, leaking, swollen, or frozen battery. Keep metal objects away from the battery, and ensure the vehicles are not touching. If you’re unsure, consult the owner’s manual for your specific vehicle, especially for hybrids, vehicles with start/stop systems, and EVs.

What You’ll Need

These items help ensure a safe and effective jump-start and reduce the risk of damaging either vehicle’s electrical system.

• Jumper cables: 4-gauge (or thicker) copper or copper-clad, with heavy-duty clamps; 12–20 feet long.
• Donor vehicle with a healthy 12-volt battery (or a quality jump pack/booster rated for automotive use).
• Owner’s manuals for both vehicles to locate proper jump points and any model-specific requirements.
• Personal safety gear: eye protection and gloves.
• Clean, unpainted metal grounding point on the dead vehicle (or a designated negative/ground post).

Having the right tools and knowing your connection points reduces confusion and limits the risk of sparks near the battery.

Step-by-Step: Connecting and Starting

Follow this sequence precisely. It’s designed to minimize the chance of a short circuit, battery gas ignition, or damage to sensitive electronics.

1. Park safely: Place vehicles nose-to-nose or side-by-side without touching. Engage parking brakes; put transmissions in Park (automatic) or Neutral (manual). Turn off lights and accessories; remove keys if required.
2. Verify voltage: Both vehicles should have 12-volt systems. Do not use a 24-volt heavy truck as a donor for a 12-volt car.
3. Find the correct posts: If your vehicle has designated under-hood positive (+) and negative/ground posts, use them instead of battery terminals.
4. Red to dead (+): Attach one red clamp to the positive (+) post of the dead battery (or dead vehicle’s positive jump post).
5. Red to donor (+): Attach the other red clamp to the positive (+) post of the donor battery (or donor vehicle’s positive jump post).
6. Black to donor (−): Attach one black clamp to the negative (−) post of the donor battery (or donor vehicle’s negative jump post).
7. Black to ground on dead car: Attach the final black clamp to a solid, unpainted metal point on the dead vehicle’s engine block or chassis, away from the battery and moving parts. If your car specifies a negative/ground post, use it.
8. Start the donor: Let it idle for 2–5 minutes to feed some charge into the dead battery. Slightly raise idle (1,500–2,000 rpm) if safe and necessary.
9. Start the dead vehicle: Try cranking for up to 5–7 seconds. If it doesn’t start, wait 1–2 minutes and try again. Avoid repeated rapid cranking to prevent damage.
10. Stabilize: Once the dead vehicle starts, keep both running for 3–5 minutes to stabilize voltage and reduce the chance of stalling when you disconnect.

This order reduces spark risk near the battery and helps the dead battery accept a charge before the first start attempt.

Disconnecting the Cables (Reverse Order)

Removal in reverse order limits the chance of accidental shorting and voltage spikes.

1. Remove black clamp from the dead vehicle’s ground point.
2. Remove black clamp from the donor battery (−) or negative post.
3. Remove red clamp from the donor battery (+).
4. Remove red clamp from the dead battery (+).
5. Keep the revived vehicle idling for at least 15–30 minutes or drive it to allow the alternator to recharge the battery.

Avoid letting the clamps touch each other or any metal while removing them. Keep hands, hair, and clothing clear of belts and fans.

If the Engine Still Won’t Start

These checks can help you decide whether to try again or call for service.

• Check connections: Ensure all clamps bite clean metal and the positive/negative polarities are correct.
• Wait and retry: Let the donor run 5–10 more minutes; then attempt another start.
• Look for signs of a bad battery: Bulging case, rotten egg smell (sulfur), or extreme age (5+ years) may mean replacement is needed.
• Consider other faults: A failed starter, blown fuse, corroded terminals, or immobilizer issues can mimic a dead battery.
• Use a jump pack: A properly sized lithium or lead-acid booster may deliver higher cranking amps than a small donor car.

If repeated attempts fail, it’s safer to seek roadside assistance or a professional diagnosis to avoid damaging electrical components.

Special Cases and Modern Vehicles

Vehicles with start/stop systems or AGM batteries

These often have specific jump-start posts and procedures. Always use the designated posts and follow manual instructions to protect battery management systems.

Hybrids

Most hybrids have a conventional 12-volt battery for accessories and control modules. You can typically jump-start the hybrid’s 12-volt system using another 12-volt source, but do not jump the high-voltage system. Use only the under-hood jump points the manufacturer specifies.

Electric vehicles (EVs)

Many EVs can be jump-started at the 12-volt battery to power up the control systems, but manufacturers often advise against using an EV to jump-start another vehicle. Check the EV’s manual for exact guidance and connection points.

Diesels and 24-volt systems

Heavy-duty diesels may use 24-volt systems or dual batteries. Do not mix voltages. Use a compatible booster or follow the specific manual instructions.

Aftercare: Protecting Your Battery and Electronics

After a successful jump, the alternator will recharge the battery while you drive, but a deeply discharged battery may not recover fully. Consider a slow charger (smart maintainer) overnight, especially in cold weather, and test the battery and charging system soon after.

Common Mistakes to Avoid

These frequent errors can cause sparks, damage electronics, or leave you stranded again.

• Reversing polarity (red on −, black on +). Double-check symbols before clamping.
• Clamping the final black lead to the dead battery’s negative post instead of a remote ground (unless the manufacturer specifies otherwise).
• Letting vehicles touch or allowing clamps to contact each other or metal surfaces.
• Ignoring dedicated jump posts and clamping directly to difficult-to-reach battery terminals.
• Jumping a damaged, frozen, or leaking battery.
• Disconnecting immediately after the engine fires; give it a few minutes to stabilize first.

A careful approach prevents most mishaps and extends the life of both vehicles’ electrical systems.

Quick Reference Recap

For clarity, here is the connection order you should remember.

1. Red to dead (+)
2. Red to donor (+)
3. Black to donor (−)
4. Black to ground on dead vehicle
5. Start donor, then start dead vehicle; remove in reverse order

If your car provides dedicated jump posts, always use them in place of battery terminals.

Summary

To use jumper cables safely: connect red to the dead battery’s positive, red to donor positive, black to donor negative, and black to an unpainted ground on the dead vehicle; start the donor, then the dead car, and remove the cables in reverse order. Use manufacturer-specified jump points, avoid sparks near the battery, and give the revived car time to stabilize and recharge. When in doubt—especially with hybrids, EVs, and start/stop vehicles—follow the owner’s manual or call for professional assistance.

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.

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.

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.

Which car do you hook up first with jumper cables?

When jumping a car, you should always connect the red jumper cable first to the positive terminal of the dead battery to prevent sparks that could ignite gases and cause an explosion. The positive cable is then attached to the positive terminal of the good battery, and the black (negative) cable is attached to the negative terminal of the good battery, and finally, the other black cable is connected to an unpainted metal surface on the frame or engine of the dead car.
 
Connection Steps

1. Red clamp to the dead battery Opens in new tab: Attach the red (positive) clamp of the jumper cable to the positive (+) terminal of the dead car’s battery. 
2. Red clamp to the good battery Opens in new tab: Attach the other red (positive) clamp to the positive (+) terminal of the good car’s battery. 
3. Black clamp to the good battery Opens in new tab: Connect one black (negative) clamp to the negative (-) terminal of the good car’s battery. 
4. Black clamp to a metal surface on the dead car Opens in new tab: Connect the remaining black (negative) clamp to an unpainted, unmoving metal part of the engine block or chassis of the car with the dead battery. This provides a ground and is the last connection, keeping any spark away from the dead battery. 

After Connecting 

1. Start the good car’s engine .
2. Let the good car run for a few minutes to allow power to transfer to the dead battery.
3. Attempt to start the engine of the car with the dead battery.
4. Once the dead car is running, run both engines for about 15 minutes before disconnecting the cables.

Important Safety Tip: Always disconnect the cables in the reverse order they were connected, ending with the black cable from the metal surface on the dead car.