Bad Alternator Quick Fix And Causes

Many people are under the assumption that the battery in a car is the only component that powers each electrical component. But the truth is that the alternator in a car plays an important role when it comes to providing power to the AC of a car, and recharging the ignition and battery. If your alternator starts to fail the power in the battery will drain fast and your car will stall or struggle to start.

Why Is Your Alternator Not Charging?

There are various causes as to why a car might not be charging properly. Below is a list of a few of the more common reasons:

1.Damaged Or Worn Out Alternator

The main reason why a car stops charging usually has to do with a damaged or worn-out alternator. The bad alternator quick fix solution for this issue is to tap the alternator using a hammer while your engine is running while using a multimeter to check whether the voltage changes. In some cases, there might be an electric fault in your alternator, and even when the voltage doesn’t change, it could still be damaged.

2. Faulty Fuse

Fuses generally blow up when they have worn out or from power surges. When this occurs, current will no longer flow to your alternator. The quick fix to this problem is to refer the manual for your car to find out which fuse controls your alternator and then replace it.

3. Broken Belt

When you look closely at your radiator you will notice a system comprised of belts or pulleys that perform the function of converting “mechanical” energy into “electrical” energy. The alternator on a car will immediately fail when the belt breaks or wears out, or when the pulley has become damaged. These are parts that are usually simple to replace.

4. Wiring Problems

The alternator receives power through wires. Over time the wires may become loose, which could be the reason why your alternator is no longer charging.

5. Computer Errors

Today in modern cars, the ECU which stands for Engine Control Unit controls just about all the electrical components in a car. If there is an issue with the ECU, it can also cause your alternator to stop charging.

6. Damaged Battery

The battery and the alternator in a car work together. A new battery should provide you with a service life of at least 5 years. If the battery dies then there is no power going to the alternator. Alternators usually last longer when compared to car batteries.

How To Diagnose A Faulty Alternator

When considering a bad alternator quick fix, it becomes important to first follow a few steps to check on the functioning of the alternator:

• While your engine is running use a hammer to carefully tap the alternator. If the charge returns to normal, then the coals that are inside the alternator have worn out.

• Check on the power cable that connects to the fuse and the alternator. This is usually a 40-60 amp fuse that is situated close to the battery.

• Check on the ground cable situated between the body and the engine.

• Check on the serpentine belt to ensure that the alternator spins while the engine is running.

• Check the charging-light wire and the smaller power-supply wire.

How Does An Alternator Work?

The primary function of an alternator is to supply power to the battery in a car. When your stereo, headlights, and your AC are all running at the same time, the car needs more power to run. The battery is not able to supply power to all these components and that is where the alternator comes in. The alternator works on converting energy that is mechanical into electricity.

The alternator connects to belts that can come loose, which usually causes the alternator to fail or become faulty. To differentiate a battery issue from an alternator problem, a voltmeter is required to check on the voltage. The engine of the car should be off when checking the voltage of the battery.

A battery that is fully charged should give a reading of 12.65 volts when the engine is off. From here turn your engine on and then check on the voltage again. The reading should be between 13.5 and 14.5 volts. This indicates that your alternator is providing charge to your battery.

The Symptoms Of A Bad Alternator

1. Battery Issues

The battery in a car is not able to charge every electrical component in the vehicle. These processes are continuous when the engine runs. When the charge on your car battery is not restoring, you will start to notice issues when it comes to starting your car. From here the lights will start to flicker.

The battery is generally the first issue when you start to experience issues with the electrical currents in a car. If for example, you need jumper cables to get your car started and the car continues to run fine after you have started the engine, then the issue usually lies with the battery and not the alternator.

2. Slow Engine Cranks

If your alternator is faulty, the engine on your car will slowly crank, and in some cases, it won’t crank at all. It is important to check on your ignition system first before deciding whether your alternator is to blame. If your engine refuses to crank and you hear a squealing or buzzing noise coming from under the car’s hood. This might be a worn-out or loose serpentine belt.

3. Battery Light

If your alternator is no longer charging the car’s battery you will notice a red “charge” or “ALT” signal on the dashboard. This is an indication that the battery is no longer powered by your alternator. It is important to also check on the wiring as the light itself may be faulty. You might also notice dimming lights when your battery is not fully recharged.

4. Noisy Alternator

If the alternator starts to make noises there may be an issue with the pulley or belt. In some cases, the belt may be misaligned. The bad alternator quick fix solution for this problem is to replace the belt making sure the belt is properly aligned with the pulley. If you still notice noises then the alternator should be replaced.

Noises from your alternator can also arise from faulty rectifiers, rotor shafts, slip rings, bearings, stator brushes or windings. It is important to examine each component and to make sure that you replace them properly. The easiest way to check whether the noises are actually coming from your alternator involves using a vacuum-hose. After you start your engine attach the hose to your alternator if you hear noises then the alternator is at fault.

5. Alternator Voltage Leak

The diodes in an alternator are important to convert the current from your alternator into a direct current. Over time these diodes wear out, and this is when the lights in your car start dimming. An AC voltmeter can be used to check for any leakages. If the diodes are faulty they are easy to replace but you need to know the correct way to dismantle an alternator.

6. The Charge Indicator Comes On While You Are Driving

This may be caused by faulty wiring. Check on the wiring and belts that surround the alternator. A bad circuit could also cause the charge indicator light to come on while driving.

How To Repair A Defective Alternator

You can either repair your alternator on your own or take your car to a mechanic. Repairing an alternator is not difficult, but you will require a serpentine-belt diagram to put everything back together.

To maintain, repair, or troubleshoot your car, you will need repair and diagnostic information which is specific to the make and model of your car. The repair process for an alternator requires disconnecting your battery, removing the serpentine-belt, followed by unbolting the alternator. From here you can remove the connectors and the wiring. To re-install the alternator follow these steps in reverse. If you decide that it would be a better idea to take your vehicle to a local repair shop, the costs involved are not much to have your alternator repaired.


It is not possible to drive your car if your alternator is faulty. While the battery performs the function of providing power to all the different electrical components, it needs the alternator to perform these tasks. Faulty diodes, worn bearings or a loose serpentine belt, are a few common contributing factors as to why your alternator is no longer functioning the way it should.

This is why it becomes important to inspect each of the components that make up your alternator and to check for any worn parts. You can ask a mechanic to assist you with dismantling the unit and to replace any of the worn-out parts. An alternator that is good condition will be noise-free. When you start to notice noises coming from your engine, it may be an indication that the belts need to be tightened.