How to Jumpstart a Car with Jumper Cables

To jumpstart with cables, park the donor vehicle close but not touching, turn both cars off, connect red clamp to the dead battery’s positive terminal and the other red to the donor positive, connect black to the donor negative and the other black to a clean, unpainted metal ground on the dead car, start the donor, wait a couple of minutes, then start the dead car and remove the cables in reverse order. This method works for most 12-volt systems; always consult both vehicles’ owner’s manuals and never attempt to jump a high-voltage hybrid/EV traction battery.

What to Check First

Before you pull out the cables, confirm both vehicles use 12-volt, negative-ground systems. If the dead battery is swollen, cracked, leaking, or suspected frozen (common in subzero conditions), do not jumpstart—have it inspected or replaced. Many modern cars provide dedicated under-hood jump posts; use those instead of the battery if specified. Hybrids and EVs typically can be boosted at their 12-volt terminals but must never be jump-started on the high-voltage pack.

What You’ll Need

This list outlines the essential tools and conditions that make jumpstarting safer and more effective.

• Heavy-gauge jumper cables (4- to 6-gauge preferred, long enough to reach comfortably)
• A donor vehicle with a healthy 12-volt battery (or a charged portable jump starter)
• Eye protection and gloves (recommended)
• Owner’s manuals for both vehicles (to find proper terminals/ground points)

Having the right equipment—and knowing where to connect—reduces risk of sparks, damage, or injury.

Step-by-Step: Connecting and Starting with Another Vehicle

Follow these steps in order to safely transfer power from the donor battery to the discharged one.

1. Position vehicles close enough for the cables to reach but not touching. Engage parking brakes; place transmissions in Park (automatic) or Neutral (manual). Turn off lights and accessories.
2. Identify the positive (+, usually red) and negative (−, usually black) terminals or designated jump posts. Clean off heavy corrosion if needed.
3. Connect the red clamp to the dead vehicle’s positive (+) terminal.
4. Connect the other red clamp to the donor vehicle’s positive (+) terminal.
5. Connect the black clamp to the donor vehicle’s negative (−) terminal or a designated ground point.
6. Connect the other black clamp to an unpainted metal ground on the dead vehicle—such as a solid engine or chassis ground—away from the battery and moving parts. Do not attach to the dead battery’s negative terminal if avoidable.
7. Start the donor vehicle and let it idle for about 2–5 minutes to stabilize voltage. Lightly increase RPMs to ~1,500 if needed.
8. Attempt to start the dead vehicle. If it doesn’t start, wait another 2–3 minutes and try again.
9. Once the dead vehicle starts, keep both engines running. Do not let the clamps touch any metal or each other.

This sequence minimizes spark risk near the dead battery, allows voltage to build, and helps modern charging systems support a clean start.

Disconnecting: The Reverse Order

Careful removal prevents accidental short circuits and protects vehicle electronics.

1. Remove the black clamp from the previously dead vehicle’s ground point.
2. Remove the black clamp from the donor vehicle’s negative terminal/ground.
3. Remove the red clamp from the donor vehicle’s positive terminal.
4. Remove the red clamp from the previously dead vehicle’s positive terminal.

Stowing the cables neatly and keeping clamp jaws from contacting each other avoids sparks and prolongs cable life.

Using a Portable Jump Starter Instead

A jump pack can be safer and more convenient than another vehicle, especially in tight spaces or remote areas.

1. Ensure the jump starter is fully charged and powered off.
2. Connect the red clamp to the battery’s positive (+) terminal or designated jump post.
3. Connect the black clamp to a solid engine/chassis ground away from the battery.
4. Power on the jump starter and wait for a ready indicator (on smart packs).
5. Start the vehicle. If it doesn’t start, wait per the device instructions before retrying.
6. Power off the jump starter, then remove clamps in reverse order (black from ground, red from positive).

Follow the device’s manual—some smart clamps prevent unsafe connections and time out to protect your battery and the pack.

Troubleshooting If It Still Won’t Start

If your engine refuses to turn over after a proper hookup, consider these common causes and fixes.

• Weak donor or pack: Try a different donor vehicle or fully charged jump pack.
• Poor connections: Re-clamp to cleaner, more solid metal; remove heavy corrosion.
• Security/immobilizer issues: Lock/unlock the vehicle, or use the physical key if applicable.
• Frozen battery: Thaw indoors and test before attempting again.
• Starter or alternator fault: If lights work but the engine only clicks or cranks slowly, test components.
• Blown main fuse: A surge or prior short may have blown a high-amperage fuse near the battery.

Persistent no-starts after good connections usually point to mechanical faults or a battery at the end of its life rather than a jump procedure error.

After You Get It Running

Once the engine is on, take steps to restore charge and prevent a repeat failure.

• Let the engine run or drive for 20–30 minutes to replenish charge; avoid heavy electrical loads.
• Test the battery: A healthy, fully charged 12V battery should read about 12.6V at rest; running voltage should be about 13.7–14.7V.
• Check age: Many batteries last 3–5 years; older units merit replacement.
• Scan for parasitic drains: Dome lights, dash cams, or faulty modules can drain overnight.
• Consider a full charge with a smart charger to recondition after a deep discharge.

A brief drive may not fully recharge a deeply depleted battery; testing and, if necessary, replacement will improve reliability.

Common Mistakes and Safety Reminders

These pitfalls are easy to avoid and can prevent damage or injury.

• Reversing polarity (crossing red/black) can damage electronics—always double-check.
• Clamping onto the negative terminal on the dead battery increases spark/explosion risk.
• Connecting to battery sensor rings on some modern cars can damage the sensor—use the specified ground point.
• Letting vehicles touch can create unintended grounding paths.
• Working near moving parts—keep cables and clothing clear of belts and fans.
• Jumpstarting hybrid/EV high-voltage systems—boost only the 12V per the manual.
• Ignoring signs of a bad battery (bulging case, acid smell)—replace rather than boost.

Following the manufacturer’s instructions and respecting modern electrical systems keeps the process safe and effective.

Quick FAQs

These rapid answers address frequent concerns drivers have when jumpstarting.

• Is it safe to jumpstart in the rain? Generally yes—avoid standing water and keep clamps dry.
• How long should I wait before trying to start? Typically 2–5 minutes after connecting and starting the donor.
• Will revving the donor help? A light increase to ~1,500 RPM can help; high revs aren’t necessary.
• Can I use any car to jump mine? As long as both are 12V systems; avoid mismatched voltages (e.g., 24V trucks).
• Can an EV jumpstart a gas car? Many manufacturers advise against using an EV as a donor; check the manual.

When in doubt, consult the owner’s documentation for vehicle-specific instructions and limitations.

Summary

Jumpstarting with cables is straightforward: connect red to dead positive, red to donor positive, black to donor negative, and black to a solid ground on the dead car; start the donor, then the dead car, and remove cables in reverse. Prioritize safety—use proper ground points, avoid sparks near the battery, and consult the manual, especially for hybrids and EVs. Afterward, drive to recharge and test the battery and charging system to prevent future no-starts.

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 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.

How to jump start using cables?

First we’ll hook our positive cable onto. The positive see the red cable mixed with the red. One. We’ll hook our negative cable onto the negative battery terminal.

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.