Auto Parts and Repairs
Car Batteries

How do you know when the alternator is dead?


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2006-09-04 02:47:44
2006-09-04 02:47:44

Lots of things can go wrong. The bearing that is belt driven can fail. It can over, or undercharge your system. The best check is to check it's running voltage - it should be between 13-14.5 volts. Anything less than 12.5 and it's not charging your battery.


Related Questions

the battery will not be recharged and will soon become inoperable or discharged {dead}

Yes. If the alternator is dead and you drive the vehicle, all the power is coming from the battery and it will eventually drain completely. Also, if a diode is shorted inside the alternator, that can drain a battery.

Charge it, replace it,test the alternator,Charge it, replace it,test the alternator,

dead battery dead alternator dead voltage regulator each needs to be tested.

Fully charge the battery Check with a voltmeter (should read approx. 12.8 volts without engine running) With engine running and good alternator reading should be 13.8-14.2 if the battery is dead the car wont start. replace the battery (preferably with a new one) run the car and if it dies or wont crank again its the alternator (or possibly the alternator belt is slipping)

If the alternator has no output then the vehicle's electrical requirements must be supplied by the battery, until dead. In addition, if the alternator quits, the alternator light, located in the instrument cluster, will illuminate

Maybe the batter is dead or you got another bad alternator.

Sorry to say,but no. The alternator is the device that replaces the power that has been used from your battery.Without the alternator, the battery will get drained and not be able to recharge.

An alternator is designed to keep a fully charged battery at peak level. It is not designed to charge a dead battery. Installing a new alternator on a car with a dead battery can in some cases ruin the new alternator. Fully charge the dead battery before starting the engine.

check your battery ground and your alternator ground

if the battery is dead, there will be no ignition lights etc when u turn the key your headlights would be very dim if on at all. the alternator only works when engine is running, so if alternator is dead it will not charge the battery most auto stores will check both battery and alternator for free if you remove from car and take them to the store

Well if you can drive around for 15 to 30 min and you battery is still dead then your alternator is bad or if you put a new battery in and it go's dead avry time you run the truck then your alternator is bad

Alternator is defective, dead cell in the battery, or something is on pulling power from the battery.

Yes, alternators are designed to maintain the battery, or recharge a battery that has been slightly discharged from starting the car. When the alternator is used to recharge a dead battery, it causes the alternator work harder and longer than it is designed for, causing it to overheat, thus causing damage to the alternator. A battery charger should be used instead. They are designed for charging dead batteries. After the battery is charged, let the alternator maintain the charge.

Corroded or loose battery connections, loose alternator drive belt, defective alternator, or dead cell in the battery.

If the alternator is not producing 13.5 to 15.5 volts it is defective and needs replacing.

Output of the alternator is controlled by the voltage regulator.

Dead battery, car will not start

If you have no power to anything, and your battery isn't dead, then you more likely have a bad ground. If the battery is dead/keeps dying, there's a good likelihood that the alternator isn't charging it adequately.

That is the purpose of an alternator. The keep the battery charged and to run all the electrics on the vehicle. However it is never a good idea to allow the alternator to charge a dead battery. This will put a strain on the alternator and may damage it.

A bad alternator will not give proper power to the vehicle. Dim lights, buzz in the stereo or a dead battery could all be causes of a bad alternator.

I have a 1997 ford expedition that the alternator is not charging the battery. Had the alternator tested and it was good the battery is new. Cant find the fuse for the alternator does anyone know where it is?

You can test it your self. Start the car might be pain in butt if alternator is really dead if so let car sit for a little while and charge it self up. Also you can knock on alternator with a happer bunch of dust will fall out and it will get you enough time to drive for few day to go get new alternator and install it without car breaking down. Anyways start the car, then disconnect the negative wire on the car if it dies the alternator is dead if not then alternator is good.

There are several signs that an alternator is going bad. A few signs are dim lights, smell, warning lights, and a dead battery.

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