As the alternator and battery in your car serve similar purposes, it can be difficult to tell which part is causing problems.
Read on and find out whether your battery or alternator is bad, and the warning signs and problems to look out for.
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Is My Alternator Or Battery Bad?
Both the battery and the alternator deliver power, so it can sometimes be difficult to tell which part is to blame.
To tell if the alternator or the battery is bad, you should pay attention when you start your car.
If the car won’t start at all, the battery is dead.
If the car starts but dies after it runs, there is an issue with the alternator.
If the car runs, but won’t hold a charge, it could be either the battery or alternator that is causing the problem.
Signs of a Battery Problem
A battery can fail for a number of reasons.
Something as simple as leaving the lights on overnight can drain the battery.
Your vehicle may have a battery problem if you notice any of the following:
- Dim dashboard lights
- Dim headlights
- The engine won't start
- A sulphuric smell
Any of these warning signs can signal that your vehicle has a battery problem.
An 'eggy' smell is a sign that your battery is leaking, in which case you must have the battery replaced right away.
The battery may also be dead if the engine won't turn over or takes longer to start.
You can check this by attempting to jump start your car.
If the car stays running for a while but fails to start the next time you try, you probably have a bad battery.
If the car immediately stalls, then it is more likely to be an alternator problem.
Signs of an Alternator Problem
You alternator can fail due to old age, wear and tear or fluid leaking onto the component.
Of course, a faulty battery can also put strain on the alternator if it struggles to hold a charge.
The main signs of an alternator problem are:
- Frequent engine stalling
- Dim or flickering headlights
- Dim or flickering interior lights
- Misbehaving electrics
- A squealing sound
- A burning smell
- A dead battery
You should have your vehicle looked at right away if you notice any of these alternator issues.
Likewise, any strange sounds from the stereo, electric windows that are slow to close or a speedometer showing unusual readings can all point towards a bad alternator.
You may have a slipping alternator belt if you smell burning or hear growling.
If your alternator is failing, then the battery may not have enough charge to start the car - which is why it can be so difficult to tell if the alternator or battery is the cause of the problem.
A professional mechanic will be able to find the source of the issue for you.
How Do I Test My Alternator?
If you are certain that your alternator is causing the problem, you can test it using a voltmeter.
This device reads the voltage of your battery and can let you know if your alternator is working correctly.
You can buy a voltmeter from any good automotive shop.
Make sure that the battery is fully charged before you conduct the test.
The voltmeter should read between 12.5 and 12.8 with the engine switched off.
Next, start the engine and read the results.
If your alternator is working correctly, you should see higher readings.
If the readings remain in the 12 volt range, you have an issue with your alternator which needs to be fixed by a professional mechanic.
