Do you know how to jump start a dead car battery? With the cold winter months right around the corner, this is an important question. When the temperatures drop, the chances of a dead battery increase significantly, since low temperatures lead to sluggish batteries. The process used to jump start a dead car battery is not difficult. Knowing what to do and always having a quality set of jumper cables on hand will get you through this otherwise frustrating situation.
Jump starting your car is not complicated, but it can be dangerous if you don’t do it right. Jumper cables transmit electrical current from one car to another. Precautions must be taken to prevent dangerous electric shocks. When one end of the jumper cables is connected to a car, the metal clamps should not touch each other or anything other than the specified components on the other vehicle. Wearing rubber gloves and protective eyewear is recommended for extra safety, so keep these items with your jumper cables.
Steps to Jump Start a Dead Car Battery:
- Position the running vehicle so the vehicles face each other, about one to two feet apart. Make sure that the vehicles are not in contact with each other.
- Engage the parking brakes on both vehicles. Turn off both vehicles and remove the keys.
- Stretch out the jumper cables on the ground, making sure the clamps do not touch each other.
- Open the hood to both cars. Referring to the respective owner’s manuals, locate the batteries and battery terminals. In most cases, the two terminals on each battery will be covered in red or black, with a + or – sign on top. Make sure you are able to identify which is positive, and which is negative, as this will be crucial to the success of your jump. Dirty or corroded battery terminals should be cleaned off with a rag or wire brush.
- Attach the red, positive cable clamp to the positive (+) battery terminal of the dead battery. Make sure you have a solid connection to the battery terminal.
- Attach the red, positive cable clamp on the other side of the jumper cables to the working battery’s positive (+) battery terminal
- Connect the black, negative cable clamp to the working battery’s negative (-) battery terminal. In the vehicle with the dead battery, attach that clamp to a metal part of the car that is unpainted, as far from the battery as the cable will reach. This will ground the circuit and help prevent sparking.
- Verify that none of the cables are in contact with engine parts that will move when the engine is started.
- Start the engine of the vehicle with the working battery.
- Allow the car to run for several minutes. Depending on the age and condition of the battery, the time required to get the jump to work may vary.
- Attempt to start the car with the dead battery. If unsuccessful, allow the working vehicle to charge the battery for a several minutes longer and try again.
- Once the disabled car is running again, you can disconnect the jumper cables, starting with the black, negative cable clamps. Never allow the clamps to come in contact with each other while any part of the cables is still attached to a vehicle.
Take the charged car for a short drive to allow the battery to build up a charge and ensure your car does not die again once you turn it off.
A jump start may fail if there are other issues that need to be addressed including:
- Bad starter connection
- Fuses are bad
- Battery condition
- Faulty alternator
- Ignition switch issues