How to jump-start a car safely with jumper cables

Stop before you connect anything

Tools and materials

• A donor vehicle: a running vehicle with a healthy 12-volt battery.
• Jumper cables: one red cable and one black cable joined as a matched set. Family Handyman uses about $20 as a planning cost when you need to buy a set. 1
• Eye protection: safety glasses or goggles.
• Work gloves: gloves help protect your hands while you work around the engine bay.
• The owner's manual: the manual can identify the battery, polarity marks, and designated jump points.
• A flashlight: useful in a dark parking area. Keep the flashlight and your hands clear of moving parts once an engine is running.

Put the clamps in this order

1. Red clamp to the disabled car's positive (+) terminal or designated positive jump post.
2. Other red clamp to the donor car's positive (+) terminal or designated positive jump post.
3. Black clamp to the donor car's negative (-) terminal or designated negative jump post.
4. Other black clamp to a clean, unpainted metal point on the disabled car, away from the battery.

The step-by-step process

1. Position the vehicles. Park the donor vehicle close enough for the cables to reach both batteries. Leave enough space between the vehicles so the bodies do not touch. Put both vehicles in Park, or in Neutral with the parking brake set when the vehicle requires it. Turn both ignitions off, switch off lights and accessories, and open the hoods. The vehicles should remain stationary throughout the connection process. 1
2. Find the battery connections. Locate the positive and negative terminals on both vehicles, or locate the designated jump posts listed in the owner's manual. The positive terminal usually carries a + mark or a red cover, while the negative terminal carries a - mark. Confirm the marks instead of relying on cable color alone. 1
3. Inspect the cables. Separate the red and black clamps. Keep every clamp from touching another clamp or an unplanned metal surface. Plan a route that keeps the cables away from belts, fans, pulleys, and other moving parts. 2
4. Make the first connection. Attach the red clamp to the disabled car's positive terminal or designated positive jump post. Squeeze the clamp fully so its metal teeth grip the connection.
5. Make the second connection. Attach the other red clamp to the donor car's positive terminal or designated positive jump post. Keep the loose black clamp away from the car and from the red clamps.
6. Make the third connection. Attach one black clamp to the donor car's negative terminal or designated negative jump post.
7. Make the final connection. Attach the remaining black clamp to a clean, unpainted metal bracket or other solid metal point on the disabled car, away from the battery. A designated negative jump post takes priority when the owner's manual specifies one. 2
8. Start the donor vehicle. Start the donor vehicle and let it idle for about two or three minutes. Keep the cables away from the fan and belts. 2
9. Start the disabled vehicle. Try the ignition for a short attempt. If the engine starts, let both vehicles run while you prepare to remove the cables. If the disabled vehicle stays silent, turn the ignition off and let the donor vehicle idle for another 10 to 15 minutes before trying once more. 2
10. Remove the cables in reverse order. Begin with the black clamp on the disabled car's bare metal. Then remove the black clamp from the donor vehicle, the red clamp from the donor vehicle, and the red clamp from the disabled vehicle. Keep the clamps from touching each other or the vehicles as you remove them. 2
11. Give the restarted car time to run. Close the hoods after the cables are clear and drive the restarted car for about 30 minutes when traffic, weather, and the car's condition make that safe. If the car fails to restart after that drive, the battery or charging system needs diagnosis rather than another round of guesswork. 2

Common beginner mistakes

• Reversing positive and negative: Confirm the + and - marks before every connection. An incorrect connection can create sparks, melt cables, damage a battery, or damage vehicle electronics. 1
• Putting the final black clamp on the disabled battery's negative terminal by habit: Use clean, unpainted metal on the disabled car, unless the owner's manual names a different designated point. 2
• Letting a clamp touch another clamp: Keep the clamps separated whenever a clamp is loose. Metal-to-metal contact can short the circuit. 1
• Allowing the vehicles to touch: Reposition the vehicles before connecting the cables. The vehicles need to be close enough for reach and separate enough to avoid contact. 1
• Routing cables over moving parts: Place the cables where a fan, belt, or pulley cannot catch them. Recheck the route before starting the donor vehicle. 2
• Using a loose clamp: Re-seat a clamp so the teeth grip clean metal securely. A loose connection can prevent the car from starting even when the sequence is correct. 1
• Removing the clamps in the connection order: Reverse the sequence. Start with the black clamp on the disabled car's bare metal and finish with the red clamp on the disabled car. 2
• Trying again and again after a failed start: Make one careful second attempt after the donor has idled for another 10 to 15 minutes. Call for professional help when the connections are correct and the car still will not start. 1

What the jump-start costs

Local shop or roadside quote - DIY outlay = your estimated saving

Three verified video tutorials

• How to Jump Start a Car (With Jumper Cables or a Jump Box) — Ethos Car Care, 3:36. The video covers jumper cables and portable jump boxes, cable order, terminal locations, and common mistakes. 3

• How to Jump Start a Car: Step-by-Step Guide | Batteries Plus — Batteries Plus, 1:27. The short video shows the five-step cable sequence, reverse-order removal, and what to do after the engine starts. 4
• How to Jump Start your Car | Dead Car Battery with Jumper Cables | Step-by-Step Emergency Guide — Life On The Go, 5:57. The video reviews cable order, waiting, and basic safety checks. 5