Car Will Not Start – Battery Or Alternator?

Car won’t start up. Is it the battery or alternator? You turn the keys and the car will not start. There is not enough power to start your vehicle. What is the cause? It is common that the battery or the alternator is the cause.

A car battery has more of a chance to be faulty than an alternator. Always check the battery first. Jump start the car battery to see if the car will start.

FYI – Jump starting a car is done with booster cables. The cable transfers a current from the good battery to the discharged battery therefore causing it to have the energy needed to start. See the infographic below to understand how to jump start a car…

how to JUMP START a carInfographic – how to JUMP START a car


A faulty battery will make a clicking sound when starting the car. A fully dead car battery will not click and no sound will be heard.

If you jump start the battery and it starts your car, then you do have a faulty battery and it needs to be replaced. Drive to an auto parts store and have the battery changed once it is jump started.

NOTE: If you turn the car off after the battery was jump started, it most likely will not start back up. Try to get a new battery before turning your car off.


If the car battery is working and your vehicle will not start, then you need to look at the alternator.

To check the alternator, run your vehicle, disconnect the positive RED terminal from the battery. If your car turns off then the alternator is most likely faulty and needs to be replaced.

Check the dash lights too. If you see the lights on your dash beginning to go from bright to dim, the alternator is the cause. This is because the alternator is not working correctly with the battery.

Change out the alternator if the battery is working and you have completed the test above… disconnect the positive RED terminal from the battery and if your car turns off then the alternator is most likely faulty and needs to be replaced.

Please note: This is a simple page to attempt to show you how to start your car with a dead battery or a faulty alternator. If you notice an error or a simpler way to explain this complex car issue, please let us know any suggestions below.

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