What Causes a Car Not to Start If the Battery Is Good?

by Phil Borges // in Car

If your car is not starting when you urgently need to get somewhere, that can be an extremely frustrating experience. Especially, if you had the batteries checked recently and that is not what is causing the problem.

But there are several systems operating at the same time in a motor vehicle, in addition to the batteries. If your car isn’t starting despite having good batteries, it could be a problem with the alternator, the starter or even the fuel filter. It takes a process of elimination to know what exactly the issue is.

If you are experiencing this problem, it would be useful to learn more about what parts of your vehicle are responsible for which function. The following sections will shed light on the possible causes for your car not starting if the battery is fully charged:

Why Is My Car Not Starting but the Battery Isn't Dead?

A car or a motor vehicle may be a mechanical device (unless it is specifically an electric car) that relies on several electronic functions. If your car won’t start for some reason, there can be several causes for this other than your battery.

Sure, the first thought that may come to mind is that the battery has died. But if you have just installed a new battery or if there is no apparent reason for the battery to have died, what else could the reason be?

Even if the battery has fully drained, that may still not explain the actual problem. Your car battery can drain for several reasons, a bad alternator being one of the primary ones.

There could also be several other reasons for your car not starting if the battery is alright. If you have ruled out that it is not the battery, it could be the car’s starter, a faulty ignition switch, a clogged fuel filter, or even an empty gas tank. But start with the basics, then make your way forward.

How to Tell If Your Car Won't Start Because of Battery

Before you even proceed to narrow down reasons why your car is not starting, you first need to rule out that it is, in fact, not your car’s battery that is causing it to not start.

If when you try to start your car, it whimpers, or if the interior lights do not come on when you open the door and there is no sound when you try to turn the ignition, chances are it is your battery that is at fault. You can also turn on the headlights of the car. If they come on easily and stay on steady, without flickering, then your car batteries are not the issue.

On the other hand, jump-starting the car may get the engine running, but if the car refuses to start again once you have turned the engine off, then it is certainly a battery issue.

You can also check the headlights and if they come on easily without faltering, then it is likely not a battery issue. The process of elimination may be a laborious one, but it is the only way to narrow down what the fault may be. In any case, it is best to call for professional help as if something is wrong with the car, it will likely need some technical support. If the battery is not the visible factor that is causing the car to falter, it is all the more reason to have a professional examine the car.

How Low Should Car Battery Voltage Drop When Starting

You can check how much charge your battery has by using a multimeter. When the battery is resting and the car’s ignition is turned off, the multimeter should reflect a reading of 12.2 - 12.6 volts. This means the battery has a full charge and is in a good state to start the vehicle. If the reading is below 12.2 volts, it means the battery is either low on charge and needs to be revved up, or it needs to be changed altogether.

But measuring the resting voltage alone is not enough. You also need to get the reading when the vehicle is being cranked. This is when the battery will be under the most stress as starting the car is when most of the power from the battery is required. Once it has started, the alternator can take some load off the battery.

As soon as the car is turned on, the voltage reading will fall for a second, but it should not fall below 1o volts. If it does, it means that the battery cannot turn over and will not last even if you manage to start the car. When the car is idling, the multimeter reading should be between 14 to 14.5 volts. If it goes below that, it is another indication of the battery being weak.

Car Battery or Starter

If the interior lights are on when you open the car door, but the engine won’t turn, it is likely a problem with your starter rather than the battery. If, when you turn the key or press the push start button, you hear a clicking noise or just a grinding noise, then it could be a problem with the starter.

If you notice smoke emerging from your car after you have tried to start the engine a few times, then it is most certainly a problem with the starter. Since the starter is connected to the electrical system of your car, it can experience a fault or a short circuit. Get out of the vehicle and call immediately for assistance if you see smoke coming from your car.

Clogged Fuel Filter or No Gas

If the fuel filter is clogged due to the build-up of particles, then the gasoline will not be able to reach the engine. When that happens, the engine will obviously not have enough juice to get started. It is important to change the fuel filter as and when it is due or you risk damaging the gas tank and the engine permanently.

At times, it can also be that the fuel filter is fine, there is just no fuel in the car! The light on your dashboard controls should indicate if your gas tank is empty. If it is not giving you a warning light and you find the tank to be empty, get the wiring checked on the controls as your fuel gauge may be faulty. If you remember filling the tank recently, then check if there is a leak somewhere.

Frequently Asked Questions

If your car is not starting, that can be a very frustrating and troubling experience. There can be many more questions about a car that has a good battery but still won’t start. The following are some of those questions answered:

How Do You Tell If It's Your Alternator or Your Battery?

The battery and the alternator work in such close tandem, that at times it can be difficult to ascertain whether it is the battery that is causing a problem or the alternator.

To check, open the hood of your car and while the engine is on, remove the negative cable from the battery. If the engine stops, then it is probably a sign of a faulty alternator as it is not giving the car enough juice to keep it running.

However, a more accurate and safer technique would be to connect the alternator to a multimeter. The alternator should give a reading between 13.5-14.5. If it is lower than that, the alternator is faulty, if it is higher, it is overcharging your batteries.

What Can Cause a Car Not to Turn Over?

When one says a car won’t “turn over”, it means the crankshaft isn’t turning, which means the engine cannot start. It simply means that your car is having trouble getting started, the reasons for which can be any of the myriad ones described above. The battery is the first thought that might strike somebody, so the first step is to eliminate this as a potential cause.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.