Car care guide · Elgin Auto Sales & Service Center · Elgin, IL
How to Jump Start a Car Safely, Step by Step
A dead battery can be jump started with jumper cables and a battery in another vehicle, or with a portable battery booster pack. Done wrong, it can hurt you or damage either car. Below is the procedure as current owner's manuals write it, using the 2026 Ram 1500 and 2026 Jeep Grand Cherokee manuals as examples. Your car's own manual comes first, because jump points and steps vary by vehicle.
12 voltsthe most a booster source should supply
4cable connections, made in a set order
Last clampgoes to a ground point, never the dead battery's negative post
Reverseorder to take the cables off
The short answer
Park both cars close without touching, put them in PARK with the parking brake on and the ignition off, and turn off accessories. Connect red (+) to the dead car's positive post, then to the booster battery's positive post. Connect black (-) to the booster battery's negative post, then to an unpainted metal ground point on the dead car away from the battery, never to the dead battery's negative post. Start the booster car, let it idle a few minutes, then start the dead car. Remove the cables in the reverse order. Never jump a frozen battery.
Before you start: safety first
Both manuals give the same warnings before any cables come out:
- Do not jump start a frozen battery. It could rupture or explode.
- Do not use a booster pack or other source with a system voltage greater than 12 volts, or you may damage the battery, starter, alternator or electrical system.
- Do not let the two vehicles touch each other. That could create a ground connection and cause injury.
- Remove metal jewelry such as rings, watch bands and bracelets that could make electrical contact.
- Keep open flames and sparks away. Batteries contain sulfuric acid that can burn skin or eyes and give off flammable, explosive hydrogen gas.
- Keep clear of the radiator cooling fan whenever the hood is up; it can start any time the ignition is on.
Then set up both cars: shift the automatic transmission into PARK, apply the parking brake and turn the ignition off; turn off the heater, radio and all electrical accessories; park the booster car within reach of the cables with its parking brake on and ignition off. If the positive post has a protective cap, lift it to reach the post. Only connect to the positive post itself, never to a fuse.
From the 2026 Ram 1500 Owner's Manual and the 2026 Jeep Grand Cherokee Owner's Manual (Jump Starting: Preparations For Jump Start), read October 27, 2026.
How to connect jumper cables, in order
Keep the unused cable ends from touching each other or either vehicle while you make the connections.
- Connect the positive (+) end of the jumper cable to the positive (+) post of the vehicle with the dead battery.
- Connect the other end of the positive (+) cable to the positive (+) post of the booster battery.
- Connect the negative (-) end of the jumper cable to the negative (-) post of the booster battery.
- Connect the other end of the negative (-) cable to a good ground on the vehicle with the dead battery: an exposed, unpainted metal part of the engine, frame or chassis, away from the battery and the fuel injection system. Some vehicles have a remote negative post for this; the 2026 Grand Cherokee's is in front of the underhood fuse box.
Never connect the last cable to the negative (-) post of the dead battery. The manuals warn the spark could make the battery explode.
From the 2026 Ram 1500 Owner's Manual (Jump Starting Procedure: Connecting The Jumper Cables) and the 2026 Jeep Grand Cherokee Owner's Manual (Jump Starting Procedure, Gas Models), read October 27, 2026.
Start the car
Start the engine of the vehicle with the good battery and let it idle a few minutes, then start the engine of the vehicle with the dead battery. Do not rev the booster vehicle above 2,000 RPM; the Grand Cherokee manual says it gives no charging benefit, wastes fuel and can damage the booster engine.
Once the car with the dead battery has started, take the cables off right away, in the order below.
From the 2026 Ram 1500 Owner's Manual and the 2026 Jeep Grand Cherokee Owner's Manual (Jump Starting Procedure), read October 27, 2026.
How to remove jumper cables
| Step | Take off | From |
|---|---|---|
| 1 | The negative (-) cable end | The ground point on the vehicle that had the dead battery |
| 2 | The other negative (-) cable end | The negative (-) post of the booster battery |
| 3 | The positive (+) cable end | The positive (+) post of the booster battery |
| 4 | The other positive (+) cable end | The positive (+) post of the vehicle that had the dead battery; then reinstall its protective cap |
From the 2026 Ram 1500 Owner's Manual (Disconnecting The Jumper Cables), read October 27, 2026. The manuals warn that not following this procedure can damage the charging system of either vehicle.
Using a portable battery booster pack
Both manuals allow a portable battery booster pack in place of a second car. Follow the pack maker's operating instructions and precautions, and never use a booster source rated above 12 volts.
From the 2026 Ram 1500 Owner's Manual and the 2026 Jeep Grand Cherokee Owner's Manual (Jump Starting), read October 27, 2026.
Hybrids, plug-ins and remote jump posts
Use the posts your manual names
Many vehicles have remote jump posts under the hood instead of an easy-to-reach battery. On the 2026 Grand Cherokee, the remote positive post can be under a protective cap, and the manual says to connect only to the post marked with a positive (+) symbol, never to fuses.
Plug-in hybrids are different
The hybrid section of the 2026 Grand Cherokee manual (for the 4xe) explains that the 12-volt battery is what turns on the high voltage battery. A 4xe with a dead 12-volt battery can be jump started, but if the high voltage battery is also discharged, it must be recharged first, and the 4xe has its own procedure.
Read your own manual
The cable order above is the common one, but jump points, cautions and hybrid steps differ from vehicle to vehicle. Check the Jump Starting section of your owner's manual before you connect anything.
From the 2026 Jeep Grand Cherokee Owner's Manual (Jump Starting Posts; Jump Starting, Hybrid Models), read October 27, 2026.
If your car keeps needing a jump
Both manuals say that if frequent jump starting is needed, have the battery and charging system tested or inspected. They also note that accessories left plugged into the power outlets, such as phone chargers, draw power even when not in use, and can drain the battery enough to shorten its life or keep the engine from starting.
From the 2026 Ram 1500 Owner's Manual and the 2026 Jeep Grand Cherokee Owner's Manual (Jump Starting), read October 27, 2026.
Battery service at Elgin Auto Sales & Service Center
We service all makes and models, including battery service. If your car needed a jump, schedule a visit and ask us to look at the battery.
Our service department is open Monday to Friday 8 a.m. to 5 p.m. and Saturday 8 a.m. to 4 p.m., closed Sunday. Elgin Auto Sales & Service Center is at 1200 E. Chicago St. in Elgin. Get directions.
Schedule service online, or see our service specials.
Jump starting FAQ
What order do you connect jumper cables?
Positive (+) to the dead battery's positive post, positive (+) to the booster battery's positive post, negative (-) to the booster battery's negative post, then negative (-) to an unpainted metal ground on the car with the dead battery, away from the battery.
Why not connect the last clamp to the dead battery's negative post?
Owner's manuals warn that the spark from that last connection could make the battery explode. Use a ground point or the remote negative post your manual names instead.
How long should the booster car run before I try to start mine?
The manuals say to start the booster vehicle, let it idle a few minutes, and then start the vehicle with the dead battery. Do not rev the booster engine above 2,000 RPM.
What order do you take jumper cables off?
The reverse of how they went on: the negative from the ground point first, then the negative from the booster battery, then the positive from the booster battery, and last the positive from the car that had the dead battery.
Can I jump start a car with a frozen battery?
No. The manuals warn a frozen battery could rupture or explode.
Can I use a portable jump starter?
Yes, if it is a 12-volt booster pack. Follow the pack maker's instructions and precautions.
My car keeps needing a jump. What should I do?
Have the battery and charging system tested. Accessories left plugged in can also drain the battery when the engine is off.
Battery keeps dying?
Schedule service at Elgin Auto Sales & Service Center on Chicago Street in Elgin. We service all makes and models.
Sources
Jump starting steps and warnings are from the 2026 Ram 1500 Owner's Manual and the 2026 Jeep Grand Cherokee Owner's Manual, read on October 27, 2026; they are examples, and your vehicle's own manual may differ. Our services, address and hours are from our own website, checked the same day. Photo is of our dealership.
- 2026 Ram 1500 Owner's Manual (Jump Starting), Ram / Mopar
- 2026 Jeep Grand Cherokee Owner's Manual (Jump Starting, gas and hybrid models), Jeep / Mopar
- Service and scheduling: service hours, Elgin Auto Sales & Service Center
- Home page: address, all makes and models service, Elgin Auto Sales & Service Center
- Battery service, Elgin Auto Sales & Service Center