What are the signs that an alternator is going bad?

Answer 1

Here are some symptoms of a bad alternator:

Step 1

One of the immediate things that you may notice is that the lights on your dash and inside your car dim at random times and then seem to work again. When this happens you may notice that your engine acts strangely too. This is one of the classic warning signs of a bad alternator. This is because the alternator is beginning to fail and is intermittently not putting out enough juice to power the car.

Step 2

You may find that you have to repeatedly jump start your car after turning it off. This in and of itself isn't one of the warning signs of a bad alternator, but it is very indicative. As long as your battery is in good condition and isn't too old then this problem generally points to your alternator. This is because the alternator isn't providing enough electricity to properly charge the battery and because of this it runs down while you are driving and doesn't have enough power to restart your car. Don't ignore a problem like this or you will prematurely wear out your battery or become stranded someplace.

Step 3

A noisy alternator is another warning sign that it is going bad. This is because the bearings inside go out and you can usually hear this when your hood is open. The sound will be coming from the area where your serpentine belt and alternator are and will sound like a sort of rattling spinning noise. It will be loud enough to make you wonder if something is wrong.

Step 4

If your engine is stalling completely, that is one of the signs that your alternator is almost completely dead. Make sure that you don't drive your car in this condition and have a mechanic or technician check it right away. This means that your alternator is so shot that it can't even keep the car running and is one of the last warning signs you will get before you can't even start your vehicle.

Answer 2

One way to tell if your alternator is going bad is to start it up, preferably at night, and turn on the lights. Then turn on the the heater fan. If your lights get dimmer when you turn on the fan the alternator could be going bad. A common problem with an alternator that is insufficiently charging is having to jump start your car even after you have run it beforehand. The best way to test it is with a volt meter. You should read 13 to 14 volts across the battery while the engine is running, if you read less your alternator is insufficiently charging. Another way to test it is to take it to a parts store for a free test.

Answer 3

It is important to note that it takes a lot of battery power for the vehicle to run. The signs of a bad alternator includes dim light, warning light, weak or dead battery, and weird smell.

Answer 4

Start the vehicle then disconnect the battery. If the motor dies, you probably have a bad alternator.

Answer 5

The alternator has failed if it is incapable of providing the voltage and amperage necessary to operate the vehicle. To determine it's suitability, it must be tested.