Here's the correct procedure:
1. Safety First: Ensure both vehicles are turned OFF. Engage parking brakes on both vehicles. Never connect the jumper cables while either engine is running. Wear safety glasses.
2. Identify Terminals: Locate the positive (+) and negative (-) terminals on both vehicle batteries. They are usually clearly marked.
3. Connect Jumper Cables:
* Positive to Positive: Connect one end of the red (+) jumper cable to the positive (+) terminal of the *dead* battery.
* Positive to Positive: Connect the other end of the red (+) jumper cable to the positive (+) terminal of the *good* battery.
* Negative to Ground: Connect one end of the black (-) jumper cable to the negative (-) terminal of the *good* battery.
* Negative to Ground: Connect the other end of the black (-) jumper cable to an unpainted metal surface on the engine block or chassis of the *dead* vehicle (away from the battery). Do not connect the negative cable directly to the negative terminal of the dead battery unless absolutely necessary, and you know what you are doing. Connecting to the chassis is safer to prevent sparks near the battery.
4. Start the Good Vehicle: Start the vehicle with the good battery and let it run for a few minutes to charge the dead battery.
5. Start the Dead Vehicle: Attempt to start the dead vehicle.
6. Disconnect Jumper Cables:
* Reverse Order: Disconnect the cables in the reverse order you connected them.
* Negative First: Remove the black (-) cable from the dead vehicle's chassis, then from the good vehicle's negative terminal.
* Positive Second: Remove the red (+) cable from the good vehicle's positive terminal, then from the dead vehicle's positive terminal.
Important Considerations:
* Battery Type: Ensure both vehicles have compatible battery types (lead-acid is most common).
* Cable Size: Use heavy-gauge jumper cables appropriate for the size of your vehicle's battery.
* Corrosion: Clean any corrosion from the battery terminals before connecting the cables.
* If it doesn't start: If the dead vehicle doesn't start after a few attempts, there might be a more serious problem than a dead battery. Consider calling a tow truck or roadside assistance.
* Hydrogen Gas: Car batteries produce hydrogen gas, which is explosive. Avoid sparks and open flames near the battery.
If you are unsure about any part of this process, it's best to call a professional for assistance. Improper jump-starting can damage your vehicle's electrical system.
