Why Won't My Car Jumpstart?

A car won't start even with a jump because there is a poor connection between the cable clamps and the battery, which causes the click..click..click symptoms. Another common problem is that the key is not being recognized by the vehicle. 

Car won't jump start dead battery no power no click

If your car with a dead battery won't start, the first thing to do is check the jumper cable connections and battery terminals to ensure there is a good contact. Try reconnecting the clamps. 

If jump starting vehicle with another car, keep the cables connected and allow let the other car idle for at least 15 minutes, then try again.

If using a jump box, keep the jumper cables connected for at least 15 min then trying again. Doing so will charge the main battery, which usually is enough to start the car. 

Car wont jump start
You can test these connections by wiggling them by hand. They should be solid; if they wiggle, then you have found a problem. car won't jump start

Make sure the black clamp is connected to clean, unpainted metal. If they are not making a good connection, then 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

can't jump start car with dead battery
Many times, the problem with jump-starting 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

Car won't star key not detected

Some vehicles will have trouble jump-starting due to anti-theft devices. Sometimes when a vehicle's battery is weak, the anti-theft system can get confused. The system may prevent the vehicle from starting because it thinks it is being stolen. If the alarm is on, then the car will not start. 

manually unlock car to disable security and jump start

Try manually unlocking the driver's door with the metal key that can be removed from your key fob. 

Car won't start due to security issues

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

Car won't start due to faulty battery sensoor
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 immediately jump the dead car. Once the car starts, allow it to stay running for at least 20 min to recharge the dead car battery before it will be able to start. 

Rember that the red clamp goes on the jump starting terminal in the engine bay that has a red cap ( or battery positive terminal), which is marked with a + or as POS.

The black cable needs to be connected to a ground point on the frame. It is normal to see a small spark when you connect the jumper cable. 

By  YOUCANIC Automotive Experts

Published on: Monday, March 2, 2020.
Updated on: Thursday, December 31, 2020