What is the reason for not being able to start the car with a jump start?
3 Answers
If the car still cannot start after a jump start, it may be because the battery is severely depleted and the charging time is insufficient. You can let the rescue vehicle run for a while, wait for about 10 minutes, and then try starting the depleted vehicle. After a successful start, let the depleted vehicle run for about 30 minutes to allow the alternator to charge the battery. If it still cannot start, consider the possibility of a starter motor failure. Below are the steps for jump-starting a car: 1. When performing a jump start, use dedicated car jumper cables. Never use homemade cables or poor-quality jumper cables for a jump start. 2. When connecting the cables, follow the correct order: connect the positive terminal first, then the negative terminal. Also, make sure the positive and negative cable clamps do not touch each other, and ensure the positive cable clamp does not come into contact with any metal parts of the vehicle. 3. Before jump-starting, turn off all electrical devices in the depleted vehicle to avoid accidentally reversing the battery terminals, which could cause a short circuit and damage the vehicle's electronic components. 4. After successfully starting the depleted vehicle, be careful when removing the jumper cables. It is best to remove the negative cable first, then the positive cable, to avoid causing a short circuit.
I experienced the same situation myself that day. After jump-starting the battery with jumper cables, the car still wouldn't start, which was really frustrating. Later, I found out that the jumper cables weren't properly connected—the positive and negative terminals were loose, resulting in insufficient current. Besides this, the battery might be completely dead, and jump-starting only provides a temporary charge, whereas starting the engine requires a strong current. Another common issue is a faulty starter motor, where the engine doesn’t make any sound at all. I’ve also seen cases where the fuel pump failed or the fuel injectors were clogged, cutting off the fuel supply and preventing the car from starting. Lastly, sometimes the anti-theft system locks the engine, so you might need to reinsert the key and try again. My advice is to first check if the cables are securely connected and try a few more times. If it still doesn’t work, it’s best to call a tow truck and take it to a repair shop rather than forcing it.
I often help friends jump-start their cars. If the car still won't start after a jump, there are usually a few reasons. First, the battery itself may be severely aged, with unstable voltage after charging, failing to meet the starting requirements. Second, there might be errors in the jump-starting process, such as using another vehicle with a low battery or incorrectly connecting the positive and negative terminals, which poses significant risks. Third, there could be issues with the starting system, like a faulty starter relay or poor contact in the starter wiring, indicated by the engine making no sound. Fourth, the fuel system may be obstructed, with insufficient oil pressure to keep the engine running. The solution is to check if the wires are securely connected, use a voltmeter to test the battery's charge, and if it's below 12 volts, try replacing the battery. Regular maintenance should include monitoring the battery's lifespan, typically replacing it every 3-5 years to avoid sudden failures.
