Alternator / Voltage Issue Question
Thread Starter
Race Director
Joined: May 2005
Posts: 15,960
Likes: 21
From: West Norriton PA
St. Jude Donor '08
Alternator / Voltage Issue Question
I have a 2001 Vette.
Just got done a lot of work on it and I fired it up.
I am only getting somewhere between 12.1V and 12.6V volts with a wide fluxuation that dips as low as 10V.
Anybody got any ideas on what cause could be ?
I'm a little worn out from all of the other work and was hoping that someon ewho has experienced the same problem might have a quick remedy.
Thanks
Just got done a lot of work on it and I fired it up.
I am only getting somewhere between 12.1V and 12.6V volts with a wide fluxuation that dips as low as 10V.
Anybody got any ideas on what cause could be ?
I'm a little worn out from all of the other work and was hoping that someon ewho has experienced the same problem might have a quick remedy.
Thanks
Race Director
Joined: Sep 2004
Posts: 17,786
Likes: 4
From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Have the charging system checked. Sears will do it for free. They test the battery and the alternator to see which is not giving the proper voltage. Then tell them thanks and have your shop of choice or you do the work.
Thread Starter
Race Director
Joined: May 2005
Posts: 15,960
Likes: 21
From: West Norriton PA
St. Jude Donor '08
All of the body panels are loose, one fender is off, the interior is gutted and it needs to be inspected.
The battery was replaced with Red Top about a year ago. The car can run for hours at a time, it's just getting low charging juice.
Race Director
Joined: Sep 2004
Posts: 17,786
Likes: 4
From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Ok, then you can take the alternator and battery to Autozone, they have bench testers. BTW the redtops are not all they are cracked up to be.
Thread Starter
Race Director
Joined: May 2005
Posts: 15,960
Likes: 21
From: West Norriton PA
St. Jude Donor '08
I have testers, I was hoping for a more technical response as to what may be the problem and if there are any cures.
I am pretty good at the electrical stuff from my days in the service where I use work on electronics.
I'm thinking the diode may have went as it does not make increasing power even when I rev up the motor.
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Yes, I know that the Optima Batteries have a pretty high failure rate. My previous yellow top crapped me out on me, however I really buy them for their design (leakage) onto the wiring under neath.
I have testers, I was hoping for a more technical response as to what may be the problem and if there are any cures.
I am pretty good at the electrical stuff from my days in the service where I use work on electronics.
I'm thinking the diode may have went as it does not make increasing power even when I rev up the motor.
I have testers, I was hoping for a more technical response as to what may be the problem and if there are any cures.
I am pretty good at the electrical stuff from my days in the service where I use work on electronics.
I'm thinking the diode may have went as it does not make increasing power even when I rev up the motor.
Thread Starter
Race Director
Joined: May 2005
Posts: 15,960
Likes: 21
From: West Norriton PA
St. Jude Donor '08
The GM alternator has a voltage rugulator on it ... once the alternator is producing about 14 volts, the regulator won't let it produce a higher voltage no matter how fast it spins. If the diode goes, you should get zero voltage out of the regulator as it is the diode that turns the alternating current (AC) output of an alteernator to direct current (DC) as used in a car.
I went out and checked the battery and the alternator with a multimeter.
- The battery has a static 12.5V with the ignition off.
- With the ignition (motor running) both the battery and alternator are running between 14V - 14.5V.
I think I have a bad gauge.
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
Thread Starter
Race Director
Joined: May 2005
Posts: 15,960
Likes: 21
From: West Norriton PA
St. Jude Donor '08
I had PaceThis redo my gauges and install 300 MPH Speedo and Z06 Tach. I thing I got a bad Volt meter.
Going to give Josh a PM to see how to take care of this one.
Got 14V - 14.5V on multimeter at battery and alternator.
Thanks
Drifting
Joined: Feb 2005
Posts: 1,592
Likes: 3
From: St Louis MO
Cheers
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Thanks for the info.
I went out and checked the battery and the alternator with a multimeter.
- The battery has a static 12.5V with the ignition off.
- With the ignition (motor running) both the battery and alternator are running between 14V - 14.5V.
I think I have a bad gauge.
I went out and checked the battery and the alternator with a multimeter.
- The battery has a static 12.5V with the ignition off.
- With the ignition (motor running) both the battery and alternator are running between 14V - 14.5V.
I think I have a bad gauge.
If they agree, the problem is a wiring issue, if they disagree then it probably is the gauge.
If the DIC is showing lower voltage than your multimeter, check the following ...
The voltage shown is fed to the IPC from Fuse 19 (10 Amp) in the Instrument Panel fuse block. Check that the fuse is clean and put in a new one if you have doubts.
Check the IPC grounds. The ground is through Splice Pack SP208 to ground point G104 which is located in the engine compartment, on the frame rail almost directly below the battery.
Read Bill Curlee's EXCELLENT sticky at the top of the C5 TECH forum about electrical issues. You'll see info on the splice packs and grounding system. It is quite likely the splice pack has corrosion inside it and that may be why you're seeing such strange voltage readings.
Racer
Joined: Jul 2006
Posts: 401
Likes: 0
From: Big Bear, CA
Interesting topic......I have always had the same problem with my '98. I can hook a voltmeter to the alt and battery and it says 14-14.6 but my guage only reads 12.7 volts.
I'll check my grounds also and see if that fixes it.
I'll check my grounds also and see if that fixes it.