alternater
Race Director
Joined: Nov 2000
Posts: 10,343
Likes: 668
From: Beverly Hills (Pine Ridge) Florida
If it is still mounted and connected in the Vette, then get out a Volt Meter, and attach it across the battery.
With no load (doors closed so the interior lights are off, key off, etc.), the battery should be around 12.6 volts.
Start the engine, while the volt meter is still connected, and the voltage should be higher (somewhere north of 13.5 volts on up to 15 max.). As the battery gets charged (from being discharged from running the starter), the voltage should drop to around 13.5 to 14.1 volts.
Plasticman
With no load (doors closed so the interior lights are off, key off, etc.), the battery should be around 12.6 volts.
Start the engine, while the volt meter is still connected, and the voltage should be higher (somewhere north of 13.5 volts on up to 15 max.). As the battery gets charged (from being discharged from running the starter), the voltage should drop to around 13.5 to 14.1 volts.
Plasticman
Last edited by Plasticman; Mar 10, 2008 at 11:32 PM.
Tech Contributor
Joined: May 2005
Posts: 15,576
Likes: 118
From: Conroe Texas
If it is still mounted and connected in the Vette, then get out a Volt Meter, and attach it across the battery.
With no load (doors closed so the interior lights are off, key off, etc.), the battery should be around 12.6 volts.
Start the engine, while the volt meter is still connected, and the voltage should be higher (somewhere north of 13.5 volts on up to 15 max.). As the battery gets charged (from running the starter), the voltage should drop to around 13.5 to 14.1 volts.
Plasticman
With no load (doors closed so the interior lights are off, key off, etc.), the battery should be around 12.6 volts.
Start the engine, while the volt meter is still connected, and the voltage should be higher (somewhere north of 13.5 volts on up to 15 max.). As the battery gets charged (from running the starter), the voltage should drop to around 13.5 to 14.1 volts.
Plasticman
Wouldn't one possible outcome of a bad regulator result in 12.6 or fewer volts with the car running?
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
Maybe -- but I think this test is for the 'goodness' of the alternator; if it passes then the electrical system checks out. If the voltage is low then it could be the alternator or possibly something else.
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From: New York New York
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Check this article I wrote, it should answer any question you might have.
http://temp.corvetteforum.net/classi..._Testing.shtml
http://temp.corvetteforum.net/classi..._Testing.shtml
Race Director
Joined: Nov 2000
Posts: 10,343
Likes: 668
From: Beverly Hills (Pine Ridge) Florida
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Excessive voltage is a indicator of a bad regulator. This condition results i lamps blowing out. OR full field the alt to see if that's working correctly. However your system should not have a integrated {intrinsic} regulator. Those came in later years.
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Thread Starter
Pro
Joined: Jan 2008
Posts: 616
Likes: 1
From: Huntersville NC
I ran the car today and had a reading of 14.8 volts across the battery so it looks like the alternator is fine. Thats the good news, bad news is it looks like I have a wiring short. I have another thread going right now ("goofy battery/electrical problem") were I have been getting some real good advice on how to go about isolating my problem. Probably going to take a little work and a lot of luck. Installed a quick disconnect on the battery so I can at least go out there and drive around as we are getting up into the mid 60's all week.
Last edited by bmcnitt; Mar 11, 2008 at 05:14 PM.