How to jump start a car
To jump start a car, park the working car close without touching, switch both cars off, then clamp in this order: red on the dead battery's plus, red on the good battery's plus, black on the good battery's minus, and the final black clamp on bare metal on the dead car, away from the battery. Start the working car, wait a few minutes, then try the dead one.
Your car clicks but will not start in a grocery store lot, and a friend offers her car.
Why it matters: The clamp order matters, and knowing it turns a dead battery into a short delay.
Steps
- Park the working car close without the two touching, and switch both off, lights and radio included.
- Check both owner's manuals for jump points; some hybrids and electric cars differ.
- Look at the dead battery and stop if it is cracked, leaking or swollen.
- Clamp red to the dead battery's positive, then red to the good battery's positive.
- Clamp black to the good battery's negative, then the last black clamp to bare unpainted metal on the dead car, away from the battery.
- Start the working car and let it run for a few minutes, then start the dead car.
- Remove clamps in reverse order, keeping the ends apart, and drive for about half an hour.
Stop and call a professional if
- the battery is cracked, leaking, swollen or smells of rotten eggs
- the car still will not start after a few tries, or the battery keeps dying: a shop should test the battery and charging system
- the car is a hybrid or electric vehicle without a jump procedure in the manual
Questions to ask the professional
- Is it the battery or the charging system?
- How old is this battery, and should it be replaced before winter?
Common mistakes
- Letting the clamp ends touch while any end is connected.
- Putting the final black clamp on the dead battery itself.
- Switching off right after it starts, before the battery has recharged.
Teach this to someone
A one page sheet for showing a friend, a teenager or a parent: what to say, what to show, and one question to check it landed.
Teach: How to jump start a car
What to say
To jump start a car, park the working car close without touching, switch both cars off, then clamp in this order: red on the dead battery's plus, red on the good battery's plus, black on the good battery's minus, and the final black clamp on bare metal on the dead car, away from the battery. Start the working car, wait a few minutes, then try the dead one.
What to show
- Park the working car close without the two touching, and switch both off, lights and radio included.
- Check both owner's manuals for jump points; some hybrids and electric cars differ.
- Look at the dead battery and stop if it is cracked, leaking or swollen.
- Clamp red to the dead battery's positive, then red to the good battery's positive.
- Clamp black to the good battery's negative, then the last black clamp to bare unpainted metal on the dead car, away from the battery.
- Start the working car and let it run for a few minutes, then start the dead car.
- Remove clamps in reverse order, keeping the ends apart, and drive for about half an hour.
Where it stops
Stop and call a professional if the battery is cracked, leaking, swollen or smells of rotten eggs.
Check question
What should be off in both cars before you connect the cables?
Answer: Engines, lights and radio. Everything off avoids sparks and electrical surges.
Your checklist
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Quick quiz
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Related skills
Sources
- US national highway traffic safety guidance for drivers, 2026. Reviewed September 28, 2026.
Written in our own words from the sources above. It is general information, not advice for your situation; where a professional, your doctor or your lease says something different, follow them.
Last reviewed . First published .