How to Jump-Start Your Car

BEFORE YOU START

Make Sure a Jump-Start Is Appropriate

A jump-start is intended for a discharged 12-volt battery—not for every no-start condition.

If the battery is cracked, leaking, swollen, frozen, smoking or has a strong chemical odor, do not attempt to jump-start the vehicle. Also stop if you are unsure which terminals or remote jump points the manufacturer specifies.

Check	Why It Matters	What to Do
Battery Condition	Damaged batteries can be unsafe to connect or charge.	Do not jump a cracked, leaking, swollen or frozen battery.
Vehicle Voltage	Most passenger vehicles use a 12-volt low-voltage system.	Confirm compatibility in the owner’s manual before connecting another vehicle or booster.
Jump Points	Some vehicles use remote terminals instead of direct battery access.	Use only manufacturer-designated positive and ground points.
Polarity	Reversing positive and negative can damage electrical systems.	Identify terminals clearly before connecting cables.
Hybrid or EV	Low-voltage procedures vary by model.	Follow the exact owner’s-manual procedure and never access high-voltage components.

DO NOT JUMP-START IF...

Some Conditions Mean Stop Before Connecting Anything

Battery damage or uncertainty about the correct procedure is a good reason to call for assistance instead of taking a chance.

Battery Is Cracked or LeakingPhysical damage can make jump-starting unsafe.

Battery Is SwollenSwelling can indicate internal damage or overheating.

Battery May Be FrozenA frozen battery should not be jump-started.

Smoke or Strong Chemical OdorDisconnect from the situation and arrange professional help.

You Cannot Identify the TerminalsDo not guess at polarity or grounding points.

High-Voltage Components Are InvolvedDo not touch orange high-voltage cables or traction-battery components.

STEP-BY-STEP

How to Jump-Start a Conventional 12-Volt Vehicle

Always follow the owner’s manual if it specifies a different connection order or designated jump points.

01Position the Vehicles SafelyPark close enough for the cables to reach, but do not let the vehicles touch. Turn both vehicles off and set the parking brakes.

02Connect Red to the Dead Battery PositiveAttach one red clamp to the positive (+) terminal or designated positive jump point on the disabled vehicle.

03Connect Red to the Donor PositiveAttach the other red clamp to the positive (+) terminal on the donor battery or booster source.

04Connect Black to the Donor NegativeAttach one black clamp to the negative (-) terminal of the donor battery, if the manufacturer procedure allows it.

05Connect the Final Black Clamp to the Approved GroundUse the disabled vehicle’s designated grounding point or an approved unpainted metal ground away from the battery, as specified by the manufacturer.

06Start the Donor Vehicle, Then Try the Disabled VehicleAllow a short moment for the low battery to receive charge, then attempt to start the disabled vehicle. Do not crank continuously for long periods.

DISCONNECTING THE CABLES

Remove the Cables in Reverse Order

Keep clamps from touching each other or contacting unintended metal surfaces while connected.

01Remove the Ground ClampDisconnect the black clamp from the previously approved ground point on the started vehicle.

02Remove Black From the DonorDisconnect the black clamp from the donor negative terminal.

03Remove Red From the DonorDisconnect the red clamp from the donor positive terminal.

04Remove Red From the Started VehicleDisconnect the final red clamp from the positive terminal or jump point.

AFTER THE CAR STARTS

A Successful Jump Does Not Mean the Problem Is Solved

A discharged battery can be caused by age, a charging-system problem or an electrical draw.

01

Battery May Be Weak

An aging battery may accept enough charge to start once but fail again later.

02

Alternator May Not Be Charging

If charging output is low, the battery can discharge again even after a successful jump.

03

Electrical Draw May Be Present

A light, module or accessory can drain the battery while the vehicle is parked.

IF IT WILL NOT START

Not Every No-Start Is a Dead Battery

If the engine still will not start, repeated jump attempts may not help.

NO CRANK

Battery, Connections or Starter

If the engine does not turn over, battery condition, cable connections, starter operation or another electrical issue may be involved.

CRANKS BUT WILL NOT START

Look Beyond the Battery

If the engine cranks normally but does not start, the problem may involve ignition, fuel, sensors or another engine-management issue.

HYBRID & EV VEHICLES

Jump-Starting Electrified Vehicles Requires Extra Caution

Many hybrids and EVs still use a 12-volt battery, but jump procedures can differ significantly by model.

HYBRID VEHICLES

Use Only the Manufacturer’s 12-Volt Procedure

Do not assume the battery location or jump points are the same as a conventional vehicle. Use the exact procedure listed for the model and avoid all high-voltage components.

ELECTRIC VEHICLES

Low-Voltage Does Not Mean High-Voltage

An EV may use a 12-volt or other low-voltage system for startup functions, but the traction battery is a separate high-voltage system. Never attempt to jump or service the traction battery.

COMMON MISTAKES

Avoid These Jump-Start Errors

Most preventable problems happen before the engine is ever cranked.

01Reversing PolarityConnecting positive and negative incorrectly can damage electrical components.

02Letting Clamps TouchConnected clamps should never touch each other.

03Grounding in the Wrong PlaceUse only an approved ground point as specified by the vehicle manufacturer.

04Jumping a Damaged BatteryCracked, leaking, swollen or frozen batteries should not be jump-started.

05Ignoring the CauseIf the battery dies again, test the battery and charging system instead of relying on repeated jumps.

06Guessing on Hybrid or EV ProceduresUse the model-specific manual and never touch high-voltage components.

RELATED NUTLEY SERVICES

Repeated Jump Starts Mean It Is Time to Find the Cause

Battery, alternator and starter problems can overlap, so testing helps identify which system actually needs repair.

JUMP-START FAQ

Jump-Starting Questions

What order should jumper cables be connected?

Follow the vehicle owner’s manual first. A common conventional 12-volt sequence is red to the disabled vehicle positive, red to donor positive, black to donor negative, then black to the disabled vehicle’s approved ground point.

Can I connect the final black clamp directly to the dead battery?

Many manufacturers specify a remote or chassis ground away from the battery for the final connection. Use the exact ground point in the owner’s manual rather than guessing.

What if the car still will not start after a jump?

The problem may be the battery, connections, starter, charging system or another engine-management issue. Repeated jump attempts are not a substitute for diagnosis.

Can I jump-start a swollen or leaking battery?

No. Do not attempt to jump-start a battery that is swollen, cracked, leaking, frozen, smoking or giving off a strong chemical odor.

Why did my battery die again after a successful jump?

The battery may be weak, the alternator may not be charging properly or an electrical draw may be draining the battery while the vehicle is parked.

Can I jump-start a hybrid or EV?

Many hybrids and EVs have a low-voltage system that can sometimes be jump-started, but the procedure is model-specific. Follow the owner’s manual exactly and never attempt to jump or service the high-voltage traction battery.