GS4spinnin

Today in traffic at a total stop with the car in drive my battery light came on I give it gas and it goes away. I popped the hood and I assumed it was the loose battery terminal I tightened it ...Well it still did the same thing the radio will die and the lights will dim as well as the windows going up very slowly ...but then all of a sudden its back to life and running strong...the car has a AC delco battery in it that the pervious owner put in it and its new. I seriously hope its not the altenator as the dealership said the altenator is not covered in the powertrain. here comes 1000 bucks to spend on a altenator install and replacement....

Battery or Altenator?

Princeton

Sounds like you need to tighten the drive belts. Give that a try first. If that doesn't work - replace the battery. That you can do yourself - and its less than $100.

The final solution is the alternator.

GS4spinnin

Anyone else know of altenator going bad symptoms wouldn't the battery light stay on completely not just at idle and go aways when given gas

mooretorque

First thing, clean the battery terminals and cable clamps (remove, clean and replace), then put voltmeter across terminals. Do that before you start replacing anything. This is a problem that should be solvable w/o resorting to the shotgun method of replacing everything in sight!!!!

tn52

The voltmeter method will only be a good test if your battery was really and really and really dead. On a "weak" or "border line" battery, you will still see good and full voltage across the terminals. The reading is very misleading. I have been there so trust me. What you need to test is the "stress" charge and most if not all of our household voltmeters don't do this. I think a lot of the popular autopart stores will "stress" test your battery free.

etj1085

what you are describing is a bad alternator , don,t buy it @ the dealer you can get one @ autozone $250.00 install it yourself , it will only take a couple of hours ,just had the same problem two months ago , byt the way replace the battery @the same time if it is old , if not give it a good charging ...good luck Tracy

markpaco

I just got my Lexus GS3 back after a long 6 month storage. The battery was pretty dead when I revived it and had to charge it up for about 20 minutes. I assumed that everything was ok but lately I've noticed that it is hard to start it; as if there is not enough juice. But once I get it started (2-3 seconds of cranking), the car runs fine. Also, when I was waiting in my car for an hour waiting to cross the canadian border, the battery light went on. I gave it a rev and it went away. I think that the battery is dying since the car seems to run fine when the car is on. I will bring it to the auto parts store to get checked out.

spxChrome

Sounds like the alternator. You can test it by cranking the car and then unplugging the battery. If it is the alt the car will die because nothing is charging it.

If the alt goes out the car will run on the battery until the battery is dead.

Usually doesn't take long to run down a battery without the alt working because the battery is just for cranking the car (once cranked the alt takes over).

A friend of mine did this on my car and it pointed to the alt, but it made me nervouse to disconnect the battery while it was running but it answered my question.

I ran it to the autoshop off the battery juice and barely made it. What is tough though is an alt can come and go. So it will mess with your head.

spcrosssr

anyone heard of a battery light coming on if the alternator is putting out 15 or 16 volts instead of the normal 13.8
seems as though that's what my 92 ES300 is doing. at idle, no battery icon, revving up it puts out 15-17 volts and the battery icon come on. Bad alternator? Battery checks out good.

markpaco

that is a really high reading. Sounds like the regulator on the alternator is bad.