voltage question
Thread Starter
Intermediate
Joined: Jul 2013
Posts: 37
Likes: 0
From: Franklin TN
voltage question
Been noticing the gauge fluctuating from 12-13.5 a lot. Thought maybe the battery wasn't holding a full charge or maybe the alt is going. When I have the headlights on and roll the windows up it drops to 11.1 is this normal? Thanks
Drifting
Joined: Mar 2011
Posts: 1,412
Likes: 15
From: Richardson TX
Voltage should be between 12 and 12.5 volts with the engine off, and around 14 with the engine on.
Sounds like you probably have something wrong with the alternator. Also, keep in mind that if your alternator is not properly charging your battery, the car will leave you stranded, as the battery won't get recharged enough to start the engine again. You might think the battery is bad, but it could be that the alternator is bad instead.
Sounds like you probably have something wrong with the alternator. Also, keep in mind that if your alternator is not properly charging your battery, the car will leave you stranded, as the battery won't get recharged enough to start the engine again. You might think the battery is bad, but it could be that the alternator is bad instead.
Thread Starter
Intermediate
Joined: Jul 2013
Posts: 37
Likes: 0
From: Franklin TN
The battery seems to crank slow and I know the dealer had to jump it off "due to someone leaving a light on" just wondering if the battery has had enough or the alternator was. I was leaning towards alt but like I said most the Time it reads around 13.1-13.4
Team Owner
Joined: Jul 2006
Posts: 22,141
Likes: 4,156
From: Kannapolis NC
A common cause for what you're seeing is the connection on the starter solenoid where the red wire from the battery and the alternator make connection. Specially if you have headers, the connection heats up and corrodes under the nut. I've even seen it crystallize the bakelite around the solenoid post. After you change the alternator and it still does it, check that connection carefully.
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
I wouldn't pull the alternator until I know for sure the battery and related cables/connections are fine.As already stated, start with the simple things that are known to fail, before progressing to other areas
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Drifting
Joined: Sep 2004
Posts: 1,737
Likes: 349
From: Layton Utah
You might want to pm Evil-Twin on this. I remember a post of his several years ago that discussed this issue in depth. If I remember right the alternator is not the issue here. It could be the battery. Good luck and let us know what you find out.