When Your Automatic Car Won't Start
Discovering your automatic car won't start can be a moment of unwelcome surprise, particularly if the engine simply clicks or remains stubbornly silent. This common issue is often down to a flat battery, which can happen for a number of reasons, from leaving lights on to the battery simply reaching the end of its service life. Fortunately, with the right equipment and a clear understanding of the procedure, you can often get your vehicle running again using another car. This article outlines precisely how to jump start an automatic car, ensuring the process is carried out safely and correctly to avoid damage to either vehicle's electrical systems.
- Connect jump leads correctly to avoid electrical damage.
- Ensure both vehicles are compatible for jump-starting.
- Follow a specific sequence for connecting and disconnecting.
- Understand the role of the automatic gearbox in the process.
The fundamental principles of jump-starting a car remain consistent across most vehicle types, but an automatic transmission introduces a few crucial considerations. Unlike manual cars, where you can immediately disengage the clutch and put the car in neutral, an automatic gearbox requires specific positioning to facilitate the jump-start. This guide focuses on these nuances, providing a reliable method for anyone needing to revive their automatic vehicle.
When faced with a flat battery, the immediate urge might be to panic, but a calm, methodical approach is key. The process involves using a second, functioning vehicle and a set of jump leads to transfer power from the donor car's battery to the dead one. It's essential to understand that this is a temporary fix to get you moving again, and the underlying cause of the flat battery, or the battery itself, will likely need further attention.
Understanding Your Automatic Gearbox
An automatic transmission operates differently from a manual one. Instead of a clutch pedal, it uses a torque converter or a dual-clutch system to manage power delivery. For the purpose of jump-starting, the most critical aspect is understanding the 'Park' (P) and 'Neutral' (N) positions. When jump-starting, the vehicle being jumped must be in Park, as this engages the parking brake mechanism and ensures the vehicle cannot roll. While Neutral might seem like a logical choice, Park is the designated and safest position for an automatic when stationary and not in active use, including during a jump-start procedure. Always ensure the handbrake is also firmly applied for an added layer of security.
The car's electrical system, particularly the alternator, is responsible for charging the battery while the engine is running. A flat battery means the car's electrical components, including the starter motor, don't have enough power to function. Jump-starting essentially bypasses the flat battery's inability to hold charge, allowing the donor car's battery to provide the necessary surge of power to crank the engine. Once the engine is running, its alternator can begin the process of charging the car's battery.
Before you begin, it's worth checking the condition of your jump leads. Ensure they are of sufficient gauge for your vehicle's needs (larger engines require thicker cables) and that the clamps are clean and free from corrosion. Damaged leads or poor connections can prevent a successful jump-start or, worse, cause electrical faults.
The primary goal is to re-establish a working electrical connection to get the engine running.
Gathering Your Equipment and Preparing the Vehicles
To successfully jump start an automatic car, you'll need a few key items. Firstly, a pair of heavy-duty jump leads is non-negotiable. These should be long enough to reach comfortably between the two vehicles without straining the cables or forcing them too close together. Secondly, you'll need a second vehicle with a healthy, charged battery that is compatible with yours. Generally, vehicles with similar engine sizes are best, but any functioning petrol or diesel car can usually provide the necessary boost. It's also prudent to have a pair of protective gloves and safety glasses, as working with car batteries involves handling potentially corrosive materials and electrical currents.
Once you have your equipment ready, the next step is to position the vehicles correctly. They should be close enough for the jump leads to reach easily, but not touching. Often, parking nose-to-nose or side-by-side works best. Ensure both vehicles are switched off, and crucially, that the ignition is off in both cars. For automatic cars, place the gear selector into 'Park' (P) and firmly apply the handbrake. For the donor vehicle, its gear selector should be placed in 'Park' or 'Neutral' with the handbrake also applied. Open the bonnets of both cars and locate the batteries. If the batteries are not easily accessible, you may need to identify the designated jump-start terminals under the bonnet, which are usually marked with a '+' or '-' symbol, or a red or black cover.
It’s vital to ensure the battery voltage is the same for both vehicles, typically 12 volts for most passenger cars. Connecting batteries of different voltages can cause serious damage. Always consult your car's manual if you are unsure about battery location or terminal identification. A quick visual check of the batteries for any signs of damage, such as cracks or leaks, is also advisable before proceeding.
Before connecting any leads, wipe down the battery terminals with a wire brush or a clean cloth if they appear corroded; a clean connection is essential for effective power transfer.
Ensure both vehicles are in a safe, stable position before commencing any connections.
The Step-by-Step Jump Start Process
Connecting the jump leads requires a specific sequence to prevent sparks and potential damage to the electronics. Incorrect connection is the most common cause of problems when jump-starting cars, so precision is paramount. The process is as follows:
- Connect the Red (+) Lead: Attach one end of the red jump lead to the positive (+) terminal of the flat battery. Then, connect the other end of the red lead to the positive (+) terminal of the donor battery.
- Connect the Black (-) Lead: Attach one end of the black jump lead to the negative (-) terminal of the donor battery.
- Connect the Final Black (-) Clamp: This is the crucial step for safety. Connect the other end of the black lead to an unpainted metal surface on the engine block or chassis of the car with the flat battery. This should be as far away from the battery as possible to minimise the risk of sparks igniting any hydrogen gas that might have accumulated around the battery. A sturdy bolt or bracket on the engine block is usually a good choice. Never connect the final black clamp directly to the negative (-) terminal of the flat battery, as this can create a spark near potentially flammable battery gases.
Once all connections are secure, start the engine of the donor vehicle. Let it run for a few minutes, ideally at a slightly increased RPM (around 1500-2000), to begin charging the flat battery. After a few minutes, try starting the engine of the car with the flat battery. If it starts, great! If not, let the donor car run for another few minutes and try again. If it still fails to start after a couple of attempts, there may be a more serious issue than just a flat battery, or the battery may be completely beyond recovery.
If the car starts, allow both vehicles to remain connected for a few more minutes while the donor car's engine continues to run. This helps to stabilise the charge in the flat battery and ensures the car's own alternator can take over. Do not rev the donor car’s engine excessively; a steady, slightly increased idle is sufficient.
The correct order of connection is critical for preventing electrical surges.
Disconnecting the Jump Leads Safely
Once the engine of the formerly flat car is running smoothly, you can proceed with disconnecting the jump leads. This process must also be done in a specific order to prevent sparks and electrical damage. It is the reverse of the connection sequence:
- Disconnect the Black (-) Lead: Remove the black jump lead from the unpainted metal surface on the engine block or chassis of the car that was jumped. Then, disconnect the other end of the black lead from the negative (-) terminal of the donor battery.
- Disconnect the Red (+) Lead: Remove the red jump lead from the positive (+) terminal of the car that was jumped. Finally, disconnect the other end of the red lead from the positive (+) terminal of the donor battery.
After disconnecting the leads, it is highly recommended to keep the engine of the car that was just jump-started running for at least 20-30 minutes. Driving it around, or even just letting it idle at a slightly higher RPM, will allow the alternator to charge the battery sufficiently. If the battery is old or faulty, it may not hold a charge, and you might find yourself in the same situation again soon. In such cases, a replacement battery will be necessary. If you've had to jump-start your car multiple times, it's a strong indicator that your battery needs to be tested and likely replaced.
Remember that jump-starting is a temporary solution. The underlying reason for the battery's depletion needs to be investigated. It could be a sign of a failing battery, an alternator issue, or a parasitic drain on the electrical system. A qualified mechanic can diagnose and resolve these deeper problems.
Never attempt to jump-start a frozen or visibly damaged battery, as it could explode.
If your car has a start-stop system, ensure it is deactivated or that the battery is sufficiently charged before attempting to jump-start it, as these systems can be sensitive to low voltage.
Always allow the engine to run for a significant period after disconnecting to ensure the battery receives a substantial charge.
What to Do Next and When to Seek Professional Help
Once your automatic car is running, it's crucial to understand that the jump-start was a temporary measure. The battery needs time to recharge, and ideally, you should drive your car for at least 20-30 minutes, or longer if possible, to allow the alternator to replenish the charge. A short trip around the block might not be enough, especially if the battery was severely depleted. If your car starts and runs normally after the jump-start, you might be tempted to forget about it, but this is where issues can resurface.
Pay attention to how your car behaves in the coming days. If the battery dies again shortly after, it's a clear sign that the battery itself is failing and needs replacement. Most car batteries have a lifespan of about 3-5 years, and beyond that, their ability to hold a charge diminishes significantly. You can take your car to a garage or an auto parts specialist to have the battery tested. They can determine its health and advise whether it needs replacing.
Furthermore, a flat battery isn't always the battery's fault. The alternator is responsible for charging the battery while the engine is running. If the alternator is weak or failing, it won't charge the battery adequately, leading to it going flat. Other issues, like a faulty starter motor or a parasitic drain (where something in the car is drawing power when it shouldn't be), can also cause a battery to deplete. If you experience repeated flat batteries, it's essential to have a professional mechanic diagnose the problem. They have the tools and expertise to test the alternator, check for electrical drains, and identify any other underlying issues that might be affecting your car's starting system.
Regular checks of your car's battery condition can prevent unexpected breakdowns.