Symptoms of A Bad Alternator: The most common signs

symptoms of a bad alternator

An alternator is one of the Main Parts of Car Electric System. It Produces the Power for your car Electric Systems. Every vehicle contains an alternator. It’s mostly important for Hybrid Cars. When the Engine is Running the alternator Produces Power and get the Battery charged. Besides, it Supplies the Necessary Electric power to the all-electric system. Alternator Operate by the Drive Belt which is connected to the  Pulley with the Engine.

We hope you understood what is an alternator. Besides, we have discussed the symptoms of a bad alternator in this article. You’ll get to know the Solutions and how to get more life for your alternator after finishing this article.

Different Types Of vehicles have different brands of Alternators. A brand new car Alternator does not get damaged within 10 to 12 years if there’s not an accident. Sometimes, it may happen when you do modifications to your car. Though modifying is not recommended by the manufacturer.

Check available Alternator in markets

Symptoms of a Bad Alternator:

There are many Symptoms of bad quality Alternator. Here we will discuss what are the signs of a bad alternator.

Battery light stays on:

Car battery light stays on and it means something wrong. It could be Battery problem, Alternator Problem, Any Kind of Loose Connections of Battery Terminal or blown alternator fuse. You Should Confirm What the Actual problem is. If You Don’t know how to check it, you should go to the auto Shop For checking and solving the issue.

If your alternator is dead, replace it or take advice from mechanics if it’s possible to repair. Sometimes minor parts like rectifier, alternator diode or relay make the problems and you can solve the alternator issue within minor cost.

Car Lighting Systems become dim:

If you observe your car lighting system becomes dim, maybe there’s something wrong with your alternator. Besides, you’ll face such problems Like Wiper blade, Indicator Light, and door/ window glass motor is inactive. Also sometimes your air conditioning system may not work. If you drive at night you can easily understand. But you must confirm the problems. And take the next steps for solving.

Car battery gets discharged:

Another important symptom is the car battery gets Discharged. Sometimes car battery keeps dying though the alternator is good. So, you check both battery and alternator. You should check the alternator with avo meter. Most importantly, check the alternator output voltage. It will be 12.6 v when your engine is off and 14.2 v when the engine starts. keep in mind we’re talking about 12 Volt alternator. In a diesel-run vehicle, or Some heavy vehicle have 24-volt Alternator.

Alternator Sound:

In-car Engine, there are lots of components. Experts Can Understand What’s the problem by hearing the Sound. Sometimes alternator Bearing or Pulley Can Be Jammed and make a grinding or whining noise. If you find out problems earlier, in some cases only bearing replacing can solve the problem.

Visual Inspection:

You can understand the Symptoms of a bad alternator. You can check the body of the alternator and if it looks dirty or like burning maybe there’s a problem. Besides, the alternator belt will be loosened.

Unwanted Smell:

You may feel some unwanted embarrassing smells. If you feel, there’s maybe a problem with your alternator. So you should have it checked by your mechanic or you should replace it if it’s totally damaged.

Suddenly Engine turns off:

While driving if your engine turns off, it may be an alternator problem. Fuel Injectors need Electric power for injecting the fuel.

How to Diagnose the Bad Alternator:

If your Cars Dashboard Battery Light is on or popping up When Engine is staring, it is for Alternator or battery problem. You can use Engine Scanner ODB II if you Can Give the Code P2503 DTC (diagnostic trouble code). Code of “Charging System Voltage Low” Can Differ from Model to Model.

Sometimes Alternator light doesn’t pop up. You should check the alternator belt if its loosen or over tighten. It doesn’t allow the alternator to perform in such conditions. Sometimes you may need to replace the alternator belt if it’s not working properly.

Another important Method is you can check by Using Multimeter. You can set the Multimeter at 20DC Volt and connect the Positive and Negative Leads in the battery Terminal at same Sign positions. After that Start The Engine and Look The Output Voltage. It should be 14.2. Now check the voltage after engine off and you’ll see 12.6 volts if your alternator is perfect. If you observe fewer values, it is a sign and Symptom of a bad alternator. You can Repair or Replace it by taking suggestions from Experts.

Symptoms of A Bad Alternator

FAQ’s (Frequently asked questions)

Q. How do I know if it’s the alternator or the battery?

Very Simply Just Jump Start Your Vehicle after That You Remove the jump starter, and see what happens. If the engine continues running it is a symptom of a bad Battery.

Q. How to recognize a bad alternator?

If the Alternator is Bad, Your Car Engine Light will remain dim. If you want to be sure just Battery Terminal and remove it quickly. You’ll easily notice some changes. In this situation, you must change or repair the alternator.

Q. How long does a bad alternator last?

Bad Alternator is bad. You should understand what role an alternator plays. The battery makes the engine start and Alternator keeps battery safe from getting discharged. It also produces the necessary power to the vehicle Electric System. Normally Alternator Life is 100K to 150k Miles. In some cases, it could be less or more.

Q. With a bad alternator is it possible to jumpstart a car?

Yes, You Can but when you remove the jump start and your car lighting system may go inactive. By the by, your battery can be discharged. It would be better if you don’t drive the car with a bad alternator.

Q. Can I drive with a bad battery?

Yes, you can but when you stop the engine you cannot start the car again without any help of jump start. It would be better if you confirm your battery is completely dead so it should be replaced.

Symptoms Of A Bad Alternator – How To Diagnose A Bad Alternator ( YouTube Video )


So, these are some basic symptoms of a bad alternator. If you feel any of them or your driving experience is being interrupted for any of these, you must fix the issue by repairing or replacing.

Learn More :

Recent Posts