You’re probably going to run into an alternator problem at some point during the life of your car. What exactly is an alternator? This auto part charges the vehicle’s battery. 

Additionally, it supplies power to the vehicle’s electrical network. This powers the dashboard and other electric parts of the vehicle. The alternator, also referred to as a synchronous generator, runs on AC power at a specific range of frequency.

So how does the alternator function to do all this? The alternator converts mechanical energy into electric energy using coils wrapped around an iron core. The process uses electric induction to generate electricity. Many issues, chief among them a failed engine start and dimming dashboard and headlight lights, are brought on by a bad alternator. 

You should be aware of the fact that a good alternator charges between 13.8 and 15 volts. The battery voltage should be between 12.5 and 12.8 volts when the car is not in use. An alternator could produce up to 150 volts of voltage when there is no battery connected to the circuit. As a result, the battery serves as a buffer in the electric circuit of the vehicle. To check for a malfunctioning alternator, use a multimeter or voltmeter. As will be covered below, it is also possible to check without any tools. 

How to check an alternator with a voltmeter/multimeter

A cheap multimeter is available at any auto parts store. Use it to know if the voltage in the electrical system of your car is optimal. Additionally, it can let you know if the battery is being charged by the vehicle’s charging system. When examining the alternator with a voltmeter or multimeter, follow the steps listed below.

1. Make sure the engine is off before unplugging the battery’s -ve terminal from the hood.
   
2. Get the voltmeter ready: Make sure the voltage is set to 20 DC volts.
   
3. The alternator’s terminals should be cleaned. Mount the red cable to the -ve battery terminal and the black voltmeter cable to the +ve battery terminal. The voltage should read between 12.4 and 12.8 volts.
   
4. Replace the -ve battery terminal before starting the engine. Verify the voltage reading. It should range from 13.8 to 14.8 volts. The reading from a modern car will range from 14.6 to 14.8 volts.
   
5. Turn on all the car’s electric features, including the radio, the headlights, and the fog lights. Given the increased load, the reading should be at least 13.6 volts at this point.
   
6. Check the multimeter to make sure the reading is at least 12.4 volts after turning off the engine.
   

A reading above 14.8 volts on the voltmeter when checking the battery reading denotes overcharging. When the car is off, a reading of less than 13.8 volts indicates an undercharge. If this happens, charge the battery or replace it. 

Any readings that differ from the aforementioned values indicate an alternator problem. It would be a wise decision to get your car serviced by a mechanic at this point..

How to test for a bad alternator without a multimeter

You may encounter a problem with your vehicle outside of the city. What then can you do if you lack the necessary tools, such as a voltmeter? Here’s how to inspect the alternator without using any tools.

1. The dashboard battery light blinking is the first sign of a bad alternator.
   
2. If you don’t see this, inspect the conveyor belt  by opening the hood. The alternator may malfunction due to a damaged drive belt.
   
3. If the drive belt is in good condition, look for damage to the alternator pulley.
   
4. If the alternator appears to be in good condition, start the engine before disconnecting the battery. If the engine stalls after disconnecting the battery, the alternator is malfunctioning.
   
5. Headlights that dim when turned on are another sign of a bad alternator.
   

It’s crucial to go to an auto repair facility or a reputable mechanic if you experience any problems after performing the tests listed above. Results may, on rare occasions, point to more vehicle issues. Get a professional opinion from a trusted mechanic, before buying a new alternator. 

Signs of a faulty alternator

Often, you can tell that the alternator is damaged before you even open the hood. Although a bad alternator can result from a bad battery, the following symptoms can help you come to a decision.

1. Dashboard displays a lit battery indicator.
   
2. The car’s engine won’t start.
   
3. The car’s engine stalls right after starting.
   
4. The car doesn’t jump start
   
5. Headlights, interior lights, and battery light dimming
   
6. The vehicle’s electric systems appear to be faulty or ineffective.
   
7. When you look under the hood, the alternator is rumbling.
   
8. Burning smell from under the hood
   

Conclusion

The primary power source for all your car’s electrical parts is the alternator. It’s crucial to get the best alternator manufacturers to replace your damaged one. As for alternator replacement costs, click here.

Explore content on our website for the various alternator replacements for your car. Using a voltmeter to check for a bad alternator is the most effective method. 

In the absence of a multimeter or voltmeter, you can perform the tests listed above to see if your alternator is defective. As mentioned above it is essential to consult a trusted mechanic before investing in a new alternator for your vehicle.

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