Alternator Problem?
Thread Starter
Instructor
Joined: Apr 2013
Posts: 128
Likes: 7
From: Godfrey Illinois
Alternator Problem?
This morning I went to open my door on my 05 vette and the battery was dead. I checked the battery and it was at 5 volts. I haven't had any warning lights. I took the battery to O'Rielly Auto Parts. They charged the battery and said it was good. (only 15 months old) I put the battery back in and took it up to Autozone and had them check the alternator. They said it was a bad battery. So I took the car back to O'Rielly and they said it was the alternator? (bad diode?) I then took the car to the next closest parts store which is another Autozone. They said the alternator is going bad. (bad voltage regulator?) He said that corrosion in the alternator can cause problems and maybe just driving the car could fix it. I drove the car and the voltage stays right at 14.0 to 14.1 while driving. It drops into the mid 13's at a stop. I was wondering what you guys think? Watch it and see what happens or just change the alternator?
Team Owner
Joined: Oct 2004
Posts: 27,420
Likes: 64
From: San Clemente CA
It sounds like your alternator is okay. How did they check the battery? The only way to check a battery is with a load tester.
A new battery can be bad and yours is not even new. Good luck and keep us posted.
A new battery can be bad and yours is not even new. Good luck and keep us posted.
Thread Starter
Instructor
Joined: Apr 2013
Posts: 128
Likes: 7
From: Godfrey Illinois
The 3 places used that load tester. Watching the voltage while driving, everything looks ok. I haven't driven it since Tuesday, which isn't that long ago. Also, there is only 31000 on the car. I would imagine it is the original alternator.
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 461
From: Southern Utah
Voltage when the car is running is produced by the alternator, so it likely is fine. You need to start measuring the current drain when the car is sitting, then if significant drain is found, start pulling fuses one by one to find which circuit is drawing current when it shouldn't. I am assuming that you park it in reverse, which was required on 2005 models.
Le Mans Master
Joined: Oct 2006
Posts: 5,078
Likes: 19
From: Cumming, GA
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Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 461
From: Southern Utah
If the battery was low, it may not have had enough driving to bring it up fully. Charge it up with an external charger and then see what happens when the car sits for a few days...and of course, shut it down in reverse if it is a stick.
Team Owner
Joined: Sep 2000
Posts: 25,015
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From: Far NW 'burbs of Chicago
St. Jude Donor '13
On our 2006, the hood light was on the 10 minute timer.
However, opening or closing a door will restart the timer for the courtesy lights every time, the hood light might be on the same timer and so opening/closing a door (or the hood itself) every few minutes could keep it on forever.
However, opening or closing a door will restart the timer for the courtesy lights every time, the hood light might be on the same timer and so opening/closing a door (or the hood itself) every few minutes could keep it on forever.
Race Director
Joined: Sep 2007
Posts: 16,557
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From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
My second alternator (first one died at 800 miles) died with about 51K showing. It went in spurts and fits for a couple weeks before failing completely. Keep a close eye on the DIC.
