You’ve hooked your car up to another with jumper cables, and you sit inside and turn the key. But, nothing happens, and it still won’t start. Now, you’re going to have to check for some issues that might be causing the problem. If your car doesn’t start with jump power, check these things to get rolling again.
If you have your car hooked up to another’s battery with jumper cables, and it still won’t start, it’s likely because you need a new battery, starter, or alternator.
It’s possible that your battery has no more life left in it. That means it’s also beyond the point where a jumpstart can help it turn over your engine. A typical battery probably won’t last much longer than four or five years, so if it’s getting old, you may need to replace it.
Also, look for signs of damage, like a cracked case. That would also require replacement.
If your battery terminals have become corroded, they won’t pass the charge from the jump start properly. Or, if the terminal posts themselves have been damaged or become loose from the battery, they also might not work for a jumpstart.
Jumper cables tend to get beaten up a bit. They’re often stored out of the way, tightly rolled up, and shoved under the mat in your trunk. If they have seen better days and are frayed or covered with rust, they might not be up to the task of jumpstarting your car. If the clamps don’t have any grip strength because their springs are worn, they might not work either.
The starter on your car enables the battery’s power to start the motor. The energy passes through the starter, and if it’s not working right, it won’t ever reach the engine to crank it. You’ll just hear a clicking sound.
The alternator works in tandem with your battery. While the engine is running, the alternator charges the battery constantly so that it can provide power to your vehicle’s electrical system, like the lights and dashboard indicators. When the alternator isn’t working right, it may be difficult or impossible to jumpstart the car.
Now that you know why a jump start might not be working, here are some things to check to see if you can get going again.
Double-check that your jumper cables are hooked up correctly. Each of the four leads should be clamped firmly to its attachment point. Always follow your vehicle manufacturer’s instructions carefully. Some models have specific connections for a jump start, so don’t assume you just connect battery to battery.
Worn-out jumper cables might not pass the charge from the working vehicle to the one you are trying to jump. Check for signs of corrosion, frayed wire, or loose clamps. If the outer rubber coating is warm to the touch, they are probably not working right.
If the battery terminals on either vehicle show signs of corrosion, just shut everything down. Remove the cables, and clean the lugs. Use a stiff brush and contact cleaner. Then wipe everything down and try to jumpstart the car again.
While the jumper cables are hooked up, click the key forward, but don’t start it by turning the key all the way. If you see that the dash lights come on, or you can turn on the radio, that means your vehicle is getting power. It’s possible that if you turn the key off again and wait for a while, your battery will charge up enough to start.
Other issues unrelated to the battery or charging system may prevent it from starting. So, check for problems like an empty gas tank (add a gallon of fuel), a clogged fuel filter, or worn-out spark plugs.
The easiest way to tell if jumper cables are working is to sit in the vehicle you’re jumping and briefly turn the key or press the starting button without starting the car. If you hear the entry chime dinging, or you see your headlights come on, your vehicle is getting some power through the cables from the donor car.
If you crank the key and you hear clicking, there may not be sufficient charge. Just wait a while longer. Consider trying to jump the car with a vehicle that has a bigger battery and alternator. For instance, if you’re jumping a massive truck with a small commuter car, see if you can find another massive truck to jump it with. You may also need a new starter.
If your car doesn’t even click when you turn the key during a jumpstart, it probably needs a new battery. Or, there is a problem getting the charge through the cables from the other car. Check your connections carefully, and try a new set of cables.
If you still have questions, check out the quick answers below.
Once a battery is fully discharged, it’s unlikely a jumpstart will get your car going. There’s no harm in trying, but you’re probably going to need a new battery.
No, a new car battery should work right away. Just make sure you’ve removed the plastic terminal connectors.
Improperly jump starting a car might damage your computer or other electronics. Always follow the manufacturer’s instructions.
If the dead battery is only partially discharged, a couple of minutes of charging time will be sufficient to get it started. If your battery is badly discharged, or the donor vehicle doesn’t put out much juice, you may need to charge it longer.
You should drive or idle the car for at least an hour after a jump start for the alternator to fully recharge the battery.