1. Park in a safe location:
- Pull over and park both the working car and the BMW 740i as close together as possible. Make sure the two vehicles are not touching each other.
2. Turn off the engines and apply the parking brakes:
- Turn off the engines of both vehicles. Apply the parking brakes to both vehicles to prevent unintended movements.
3. Locate the battery for both vehicles:
- Open the hoods of both vehicles to access the batteries. The battery in the 740i is located in the trunk.
In the working car, the battery is usually located in the engine compartment. Refer to your owner's manual for the exact location.
4. Identify the battery terminals:
- Both batteries will have two terminals: a positive terminal (usually marked with a "+" symbol or red color) and a negative terminal( usually marked with a "-" symbol or black color).
5. Connect the jumper cables:
- Connect one end of the red (positive) jumper cable to the positive terminal of the dead battery in the 740i.
- Connect the other end of this cable to the positive terminal of the working car's battery.
6. Connect the black (negative) jumper cable:
- Connect one end of the black(negative) jumper cable to the negative terminal of the working car's battery.
- Connect the other end of this cable to an unpainted metal surface on the 740i, such as a bolt, that is not near any fuel lines. This is done to avoid potential sparks.
7. Start the working car and let it run for a few minutes:
- Start the engine of the working car and let it run for a few minutes.
- This will allow the working car's battery to charge the dead battery in the 740i.
8. Try to start the BMW 740i:
- After a few minutes, try to start the BMW 740i. If it starts, leave it running for a few more minutes to ensure that the battery is sufficiently charged.
9. Disconnect the jumper cables in the reverse order:
- Disconnect the jumper cables in the reverse order that you connected them. Start by removing the black (negative) cable first and then the red (positive) cable.
10. Test the BMW 740i battery:
- Once the jumper cables are disconnected, take the BMW 740i for a short drive to allow the alternator time to fully recharge the battery. Monitor the battery voltage using the vehicle's instrument panel to ensure it is within the normal operating range.
11. Check the charging system.
- If you experience persistent battery issues, there may be a problem with your charging system. To ensure the alternator and other components are functioning properly, consider taking the vehicle to a reputable mechanic or auto repair shop for diagnosis and potential repair.
