Battery light is on- why?

[Vito117]

I just noticed my battery light came on...
My battery is a Die Hard...seems to be OK still
Is this one of another "little" suprises this freakin car has in store for me?

 

[MobileSHO]

it is ur starter probley bc mine did that to me i had to replace the starter

 

[Mr Anonymous]

The battery light indicates a charging system problem. Your best bet would be to take the car to a place like AutoZone for their free charging system diagnosis.

Usually, if the battery properly holds a charge at the correct voltage, the light indicates an alternator problem. Every car is different, so I wouldn't put too much faith in the other member's assertion above that your starter is the problem. The only way to find out for sure is to have the charging system tested.

You didn't mention in you posting or your profile if your car is an ATX or MTX. They use different alternators that vary widely in price, so if the alternator is indeed the culprit, you could be looking at anywhere between $80 and $300.

 

[SHOZ123]

Does anyone for sure know the logic behind the workings of the Battery Light? With my alternator cut out, on my old alternator, the battery light would light when the alternator was disabled. Now with the new alternator the light may flicker once when the alternator is re-inabled but during the time the alternator is off the battery light is not on.

 

[Rob94]

The battery light is supposed to come on when the voltage in the charging system drops below 12 volts, and I believe when it goes over 15 volts. The most common cause for the battery light to come on is a bad alternator. It can also come on if there is a bad ground or any other reason why the system is reading below the minimum voltage. I have never heard of a battery light coming on because of the starter. The starters only function is to turn the engine over for starting. Once the engine is running, the starter does nothing.

 

[Vito117]

Its a 93 ATX
134k

If it is the alternator can I buy a factory reconditioned one, from Autozone or someplace.
So many Tarusus out there....I gotta think they are the same?

is there a way to test alternators to see if they are going bad?
How much am I looking at here?

 

[Ishodu]

The alts are far from the same. Once you open up that hood you are in a whole new world..

 

[Jr's Sho]

Well said Rob, and it's good to hear from you! I replaced mine in my ATX recently, cost: $190 shipped from NAPA. I think the ATX uses a higher amp output version and therefore cost a little more than the MTX. It was a pretty straight forward job, it's up to you whether you want to get it rebuilt or get a replacement.

 

[F-22 Raptor SHO]

Jr: Before you run out and buy an alternator, check one thing that has plagued me 3 times now: I also have an atx. Pop the hood. Look at the thick wire coming up to the alternator. The end is covered by a little boot kinda like a spark plug cover on a lawn mower. There is a little brass eyelet that bolts to the alternator. Mine has broken a number of times. Im guessing because the engine flexes and the wire was short.

Worth 190 bucks to check it out.

 

[jelloslug]

Same here, I just got done fixing the same wire on mine.

 

[luigisho]

Hey jello, I saw your pics. Does it still look that bad?

 

[jelloslug]

Noooo, not by a long shot. New carpet, padding, headliner, and redyed all the plastic including the console and door panels. I'm still working on the leather though.

 

[Jr's Sho]

I agree, when I took that cable off the alternator, the metal piece farther down the cable broke into two, it actually looked like someone clamped the two pieces together instead of getting a new battery cable. I don't think that is the sole factor in setting the light off, my alternator was the original one from 1995 with 110,000 miles on it. My light came on and stayed on longer and longer until the battery couldn't charge the rest of the car.

 

[Ian]

The battery light is part of the charging circuit. There is sometimes a very small resistor (abt 30 ohms) in series with the battery lamp which then goes to the excitation circuit in the alternator. I once had a car that went through 5 alternators in less than a year (all under warranty after talking to head office of car manufacturer) because the alternator light circuit had about 3000 ohms resistance which caused the alternator to put out max current and voltage at all times the engine was running. Volt meter would drop, but if I reved engine to abt 6000 rpm alternator would start to charge until car shut off. If light comes on, have alternator checked. It could be one diode bad, loewr charge rate but ok to live with, or alternator could be cooked. lol Ian R.