Charging system problem - battery or alternator??
Thread Starter
Burning Brakes
Joined: Jun 2001
Posts: 1,048
Likes: 0
From: Harrisburg PA
Charging system problem - battery or alternator??
How can you tell its time for a new alternator vs replacing the battery? I've had this Vette for about 2 years now so I'm not sure how old the Optima Red Top battery is. I had to jump the car on Saturday morning and I let it run for about 15 minutes. Then later Saturday night I went to take her for a spin and it needed a jump again to crank over. I ran her hard for about 30 minutes and put her away for the night....now its Monday and I just tried to turn her over and it near dead again. The alternator does make a ticking noise but I believe its done that since day one.
What do you guys think? Replace the Red Top or take her to the shop for a new alternator or charging test. I just hate to drop $100+ for a battery only to have to spend who knows what on a new alternator in a weeks time.
What do you guys think? Replace the Red Top or take her to the shop for a new alternator or charging test. I just hate to drop $100+ for a battery only to have to spend who knows what on a new alternator in a weeks time.
Team Owner
Joined: Jan 2006
Posts: 58,551
Likes: 95
From: The warm part of Anger Island
St. Jude Donor '09
Autozone will do the test for free in the parking lot. Sounds like a battery to me. If you do replace it, make sure it has a full charge or you will cause alternator (I think the vette is actually a generator) problems the first time you crank it over.
Team Owner
Joined: Jan 2006
Posts: 58,551
Likes: 95
From: The warm part of Anger Island
St. Jude Donor '09
Originally Posted by Silver Bullet 99
I wish I had the receipt - maybe the prev owner was smart enought to sticker it under the battery before the install. I didn't know Optima had a 4 year guar!!
I am specifically looking for a circular sticker on the side with a letter, dash, and a number.
If you do this, I can tell you where it came from and what month of what year it was bought. Most companies, if they recognize the battery as being their's will exchange/pro-rate it without the original reciept for customer loyalty.
Racer
Joined: Jun 2005
Posts: 333
Likes: 1
From: Mendota Heights MN
Check your voltmeter with the car running. If your alternator is charging, it should read approx 14.5 volts.
However, based on your symptoms, the alternator has to be working. If it needed a jump start, and the alternator wasn't charging, it probably wouldn't start to begin with -- unless you charged the battery first.
However, based on your symptoms, the alternator has to be working. If it needed a jump start, and the alternator wasn't charging, it probably wouldn't start to begin with -- unless you charged the battery first.
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Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
Do you have a volt meter? If so then check battery voltage with the engine off, you should see OVER 12 volts (12.4/5?) Now start the engine and again check battery voltage, you should now see 13.? to 14.4/5/? with the engine running. If you see your charging voltage come up then that would rule out a bad alt.
Le Mans Master
Joined: Mar 2003
Posts: 7,795
Likes: 2
From: Noblesville Indiana
CI 7-8 Veteran
St. Jude Donor '03-'04-'05
I just went through this problem with my car. I'd have to jump it to get it started. I'd drive around for an hour straight, turn it off and then try to start it after a few minutes, and no luck. I took my Optima back to where I bought it (Advance Auto) and asked them to check it. They put it in their machine and said it was a bad battery. I bought it there just about three years ago but didn't have my receipt. Luckily, the guy who sold me the battery remembered my car and said it was within the three year warranty period so I got a new Optima for free. I put it in and now my car fires right up with zero problems.
Race Director
Joined: Apr 2005
Posts: 11,138
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From: Fremont CA
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20
NCM Sinkhole Donor
Originally Posted by sunnyvette
Sounds like a battery. If it was the alternator, you'd lose power while driving and then your car will shut down while driving
Battery is for starting / alternator is for running. Your car RUNS fine. Just need a new battery 
Drifting
Joined: Jun 2002
Posts: 1,847
Likes: 1
From: Iowa
Cruise-In IV Veteran
Cruise-In V Veteran
Originally Posted by doje
Battery is for starting / alternator is for running. Your car RUNS fine. Just need a new battery If the alternator is good, it will keep running. If not, then it will stall out immediately.
Is this not a good idea with modern cars like the vette and all the computerized gadgets, or what?
