So my battery light came on today after work. Car started up fine but obviously what sprung to mind was that it may be the alternator or a failing battery (the battery is just over 1 year old though). Anyway, I drive home but with the intention of taking the car to autozone to get a diagnostic reading a couple hours later (and also hoping after an hour or so sitting, the red light would just magically disappear). Unfortunately it didn't, so I headed to autozone and got a diagnostic check. They read the battery in good health at 83% life, asked me to start the car, upon which the little diagnostic computer apparently concluded that the starter was the problem.

My question is, does it make sense that the starter is the issue..? i'm wary that it might be the alternator, but that they just didn't test that far after finding an error message with the starter... And if I haven't had any trouble starting the vehicle whatsoever, and that the red light stays on the entire time i drive (i assume that means the battery is losing power)... is it really the starter?

I drive a 2002 Honda Civic. Any help enlightening this issue would be helpful. I intend to take it to a garage tomorrow morning, but i'd like to be a little wiser about what the problem is.

Thanks for any help,

Peter

 

doesn't make sense for it to be a starter.. then again it is autozone! do the old test..start the car remove the positive terminal post and if the car dies then you know alternator if it stays on it still could be the alternator but i'd check other things first before that.. maybe fuses?

 

Check to see what kind of charging voltage you get. You should see something like 13.75V to 14.25V.

Since ignition system, as well as other systems on the car, is run by the battery, the engine would die as soon as you pull the positive cable off of positive terminal. Also if by accident you let the positive cable touch the ground (any metal part of the car at this point), you will see a tremendous spark. I have not conducted such test myself, so I am only guessing about it. I would not remove positive terminal with negative terminal still connected to the negative post, if you ask me.

 

The "battery" light is actually controlled by the alternator. It indicates a problem with the alternator, not the battery. When the alternator fails to keep the battery charged, battery will run down until the car does not work due to a "dead battery". So actually in that case the battery is not the source of the problem.

First check that the belt is still in place and tight and the alternator spins with the engine.

Do not do the disconnect the battery test. It was fine in the 1950's, but it can cause a power surge that would do expensive damage to a modern car. To check charging performance, measure the voltage at the battery with the car running. If you don't have a $20 voltmeter you have no business working on an electrical system.