Is it battery or alternater

Good Morn. Last eve when getting off work, midnight, my 03 Toyota Camary was dead. A fellow worker was good enough to give me a jump start and the car started. As soon as I turned on the lights, the car died again. After several attempts with the same resullts, I had to leave the car at work. Can anyone suggest if it is the batt. or alt. that would cause this. I am a single mom with no knowledge of autos, and would like a heads up so as not to be taken advantage of at the local shop. Thank yiu in advance, for any info.

 

It is something to do with the alternator.

The battery is just a storage of energy to start the car and then the engine, which is powered by the gasoline, supplies power to the electrical generator (alternator)
After the car is started, the electrical demands are satisfied off the electrical generator (alternator) and you could take the battery out and throw it away until the next time you want to start the car.( This is not done though because the battery acts as an accumulator to the electrical system and smooths out the electrical voltage to protect the electrical components)
After the car is started the voltage regulator reads the the battery is down some and sends current to the battery to recharge it. The current slows and stops when the battery is charged and ready again.
With your car stopping when you turn on your lights, it is a case of the electrical generator (alternator) not making electricity and the cars electrical needs drawing from the battery which is in a discharged state. The battery in its down state cant supply both the ignition to fire the spark-plugs and run the lights so it stalls.

Depending on how far and how long the battery was discharged, it may need to be replaced along with the electrical generator (alternator) problem.

 

It's sounding to me like the alternator, for the simple fact that it quit when headlights were turned on. That is one of the functions of your alternator, is to supply power for all those items, and charge your battery. It only supplies the power after the engine is running.Your battery is basically used to store the power for starting & when, or if your alternator needs a little help from time to time. One thing I would do though, is have the battery fully charged & tested, and have all your connections to the battery & alternator checked before replacing anything, as a good service facility should do. If you have any friends or neighbors with a voltage meter, and a battery charger, we can walk them through a few tests to verify what's needed, but I wouldn't be surprised if your in to another alternator.
Sorry!

 

Agreeing with the others - the car would have kept running once started if it was the battery. The battery was low and the car died after the jump because the alternator isn't working. Unfortunately, that can damage the battery, so you always want to check it as well - common to have to replace both.

 

Thank you all for your help

 

If you have faulty alt then your battery light should have come on.