battery light came on for 3 seconds then went off

Status
Not open for further replies.
Joined
Dec 10, 2002
Messages
9,367
Location
USA
lately, it's been one thing after another with my 96 sunfire. 1st, my trans, then my fuel filter was plugged. now my battery light came on. On my way home from work, I saw my battery light come on while sitting in traffic for maybe 3 seconds. Then it turned off and didn't come back on for the rest of the 8 mile drive home. The car drove normally. When I came home, I checked the battery terminals to make sure they are on tight, since I had them off two days ago to change my fuel filter. They were tight with no corrosion present. My Duralast battery is almost 1 year old. My alternator is a duralast alternator that I bought new back in 2001. I put a black and decker charger that plugs through the cigarette lighter. It's still charging the battery after an hour which is unusual. It seems to me that it's most likely the alternator, but I just drove 5.5 hours all highway last thursday, the battery should be charged. I had the battery unhooked on sat-sunday to change my fuel filter. Pretty obvious to test the alternator and battery? am I missing something?
 
Similar symptoms to when my alternator was on the outs, except the battery light would flicker occasionally when I was stopped or at low rpms. If your charger is doing a lot of work when you plug it in, you might be running on battery power at times. I would take the battery in to be checked just to make sure it isn't the problem. Then I'd probably buy a new alternator.
 
Check the serpentine belt tension, sometimes the spring in the tensioner goes kaput and it's loosey goosey.

A Digital Volt-Ohm Meter will be your friend if you want to precisely diagnose why you need a new alt.
wink.gif


Coworker's sunfire alt went kablooey and I was suprised how much the parts store rebuilds were... so got him a $30 junkyard one that's serving fine.
 
Start the car and run it for a few minutes then put a multi-meter on the battery posts and see what voltage you get. Then put on the high-beams, wipers and heater fan and check it then. If it's reading just above 12V then the battery or the alternator is weak. If you are in the 13's or higher you are OK and it could just be a bad connection on the alternator or an engine to body ground problem caused under low load.

You could also have a bad/sticking brush in the Alternator causing a poor connection.

Have the battery load tested and if it checks out, check into the alternator. You can have these tested at most part stores for proper charging.
 
I wonder if a fault was recorded by the computer. If so, it will be stored and retrievable by an OBD2 reader. More clues to help with your diagnosis.
 
Were you driving through a puddle at all? I had my serp belt slip one time, apparently the puddle was deeper than I thought and splashed on my belt. Besides the rain, my serp belt was deflecting from my [censored] tensioner. Might be something to check.
 
Many voltage regulators are designed to not charge until the alternator shaft speed reaches a certain speed. The keeps the alternator from adding a load while starting.

To put it in more technical terms, the voltage regulator (VR) provides only a small rotor current until the secondary field coil produces high enough frequency pulses. Certain clever VRs may even delay extra pulses before ramping up the rotor current to prevent belt squealing.

If your idle speed dropped low enough, the voltage regulator might have "dropped out" and re-started the ramp-up.
 
On Sunday, it did rain a ton here. Monday, the roads looked dry. I may have hit a puddle? But I did check the serp belt, it wasn't loose and I didn't feel any slack. I watched for the battery light the whole drive to work this morning on my 10 mile stop and go commute. it didn't come back on. I'm going to keep a close eye on it. I charged up my black and decker battery charger last night while I slept and I'm keeping it in my car in case I need a jump.
 
If you are going to stick with older cars getting a scangauge is a pretty good investment I think. Then you can see the actual voltage in real time, all the time if you like. You can check and clear codes and it will pay for itself in fuel savings if you pay some attention to how your driving affects your fuel consumption.
I replaced the battery on my Tracker last fall as it wouldn't hold anymore than 12.3V overnight and was turning over the engine slower. I probably could've got through the winter with that battery and then this summer but it was making the alternator work more and more trying to charge it. Hopefully the new battery will let the alternator live on for several more years.
Ian
 
My mom had a similar event in the Saturn last week, except the battery light stayed on for a full minute. It hasn't reappeared since, but I wouldn't be surprised if the alternator is on its way out again.

My current alternator is a Pep Boys ProStart Premium that was installed back in '03. It has about 63k on it right now, which is the mileage that the factory one failed at.
shocked2.gif
 
Critic,

So far, the battery light hasn't come back on.
I charged the battery through the cig lighter with my black n decker battery charger during lunch. only took 5 seconds before it said the battery was full.

I can't help but think if having the DRLs on all the time when the car is running is shortening the life of these GM alternators. I got 8 yrs/70k on this duralast gold alternator so far. It came with a lifetime warranty from autozone. I checked autozone.com, they are not giving lifetime warranty on their duralast alternators anymore. 90 days is their limited lifetime warranty now. Really, if the alternator is bad, I'm supposed to get a free one. I wonder if they will fight me on it.
 
Check you battery water level.
Then the cable ends - BOTH ends of each cable.
Clean or adjust as necessary.
Check you battery voltage with the car off, then with it running at idle, 1,500, and 2,500 RPM.
Then do this with the lights on and the fan on high.
You should get 12-12.5 V off.
Running , with everything on at mid RPMS, should get you 14V.
Any much less indicates a problem.
 
Status
Not open for further replies.
Back
Top