Why Won’t My Car Jumpstart?
A car that will not start, even with help from a jump-starter, indicates a poor connection between the cable clamps and the battery, which will cause a click..click..click sound. Another common problem is that the vehicle does not recognize the key.
If your car does not start because of a dead battery, check the jumper cable connections and battery terminals to ensure a good connection. The issue could be related to corroded battery terminals that need to be cleaned.
When jump-starting your vehicle with another car or a jump box, keep the cables connected and let your car idle for at least 15 minutes, then try again. Doing so will charge the main battery, which usually is enough to start the car.
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You can test these connections by wiggling them by hand. They should be solid; if they wiggle, you have found a problem. 
Make sure the black clamp is connected to clean, unpainted metal. If they are not making a good connection, you will only hear a click when you try to jump-start your car. It is normal to see a spark when you connect the negative.
Discharged Jump Starter
The problem with jump-starting often comes from not having a fully charged jump starter battery. Be sure that your jump box is fully charged. A weak or not charged jump box will lead to no start.
Anti-theft Security System
Some vehicles will have trouble jump-starting due to anti-theft devices. The anti-theft system can get confused when a vehicle’s battery is weak. The system may prevent the vehicle from starting because it thinks it is stolen. If the alarm is on, then the car will not start.
Try manually unlocking the driver’s door with the metal key that can be removed from your key fob.
Once you get in the car, try starting the engine by pressing the START button with the keyfob. This usually lets the anti-theft system recognize the factory key.
Battery Sensor
It can be very dangerous to jump-start some new vehicles. Many vehicles made in the last 5 years are equipped with a smart battery sensor. This is a sensor on the battery that determines the health of the battery.
These smart sensors will usually warn a driver of a battery concern before it causes a no-start. These sensors and computers can be damaged if the vehicle is jumped. They are typically found on cars less than 5 years old, especially high-end European vehicles. Always check the owner’s manual before jump-starting one of these cars.
When jump starting using another vehicle, sometimes patience is needed. You may not be able to jump the dead car immediately. Once the car starts, allow it to stay running for at least 20 minutes to recharge the dead car battery before it can start.
Rember that the red clamp goes on the jump starting terminal in the engine bay with a red cap ( or battery positive terminal), marked with a + or as POS. The black cable must be connected to a ground point on the frame. It is normal to see a small spark when you connect the jumper cable.
We hope you find the Why Won’t My Car Jumpstart guide helpful. Check these troubleshooting and repair guides for more help on your vehicle.
