Service charging system
Speedy
Joined: Mar 2007
Posts: 6,109
Likes: 931
From: Tn
2024 C8 of the Year Finalist - Modified
one theory ive heard is that the extra current draw from upgraded fuel pumps + your cooling fans draws soo much current that it sets off the alarm (does the warning come on when the car is hot only?)
you could be having belt slip if the warning is coming on during WOT runs only
if it makes you feel better i was getting this a lot, then left the car alone for 2 weeks while on vacation and ever since never saw it again
Premium Supporting Vendor
Joined: Oct 2004
Posts: 23,599
Likes: 1,224
From: Providing the most proven supercharger kits for your C5/6/7 609-752-0321
It is often a battery starting to fail. Enough to start the car fine, but it takes to long for the voltage to reach it's proper level.
Speedy
Joined: Mar 2007
Posts: 6,109
Likes: 931
From: Tn
2024 C8 of the Year Finalist - Modified
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Mine was doing this and I shot contact cleaner all over the inside of the alt and the voltage shot right up. It was fine for 2 more months and came back last night.
A rebuilt stock built for 140 amps is available from Gene Culley. I will go that route after I check the connections at the starter and change the spark plugs. The battery is a new red top.
the voltage shooting right up when I tried the contact cleaner doesnt look good for the other possibilities.
A rebuilt stock built for 140 amps is available from Gene Culley. I will go that route after I check the connections at the starter and change the spark plugs. The battery is a new red top.
the voltage shooting right up when I tried the contact cleaner doesnt look good for the other possibilities.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
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
Premium Supporting Vendor
Joined: Oct 2004
Posts: 23,599
Likes: 1,224
From: Providing the most proven supercharger kits for your C5/6/7 609-752-0321
Speedy
Joined: Mar 2007
Posts: 6,109
Likes: 931
From: Tn
2024 C8 of the Year Finalist - Modified
hmm always a possibility, its weird i was having a slow leak in one of my new tires, this service charging system issue, leave the car sitting for 2 weeks while on vacation come back and everything fixed its self, its almost like the car was afraid i was abandoning it so it cleaned up its act while i was gone - good car
Premium Supporting Vendor
Joined: Oct 2004
Posts: 23,599
Likes: 1,224
From: Providing the most proven supercharger kits for your C5/6/7 609-752-0321
hmm always a possibility, its weird i was having a slow leak in one of my new tires, this service charging system issue, leave the car sitting for 2 weeks while on vacation come back and everything fixed its self, its almost like the car was afraid i was abandoning it so it cleaned up its act while i was gone - good car
I hope it stays that way for you.
Thread Starter
Racer
Joined: Sep 2007
Posts: 357
Likes: 0
its weird i had the same problem, how many miles have you had your sc on? if you have high mileage and a lot of sc miles the added tension from the sc could have worn out your alternator
one theory ive heard is that the extra current draw from upgraded fuel pumps + your cooling fans draws soo much current that it sets off the alarm (does the warning come on when the car is hot only?)
you could be having belt slip if the warning is coming on during WOT runs only
if it makes you feel better i was getting this a lot, then left the car alone for 2 weeks while on vacation and ever since never saw it again
one theory ive heard is that the extra current draw from upgraded fuel pumps + your cooling fans draws soo much current that it sets off the alarm (does the warning come on when the car is hot only?)
you could be having belt slip if the warning is coming on during WOT runs only
if it makes you feel better i was getting this a lot, then left the car alone for 2 weeks while on vacation and ever since never saw it again
Thanks!
Melting Slicks
Joined: Sep 2004
Posts: 3,287
Likes: 1
From: Union City CA
Are you getting the service message when moving or just at idle?
I have heard from other guys that if you are getting the service message only at idle then it might be that the battery is going bad.
I have heard from other guys that if you are getting the service message only at idle then it might be that the battery is going bad.
Former Vendor
Joined: Jul 1999
Posts: 2,103
Likes: 0
From: Indianapolis Indiana
St. Jude Donor '11
What we used to find the problem to be when I worked at the dealership of the C5's and today my buddys working on the C6's is aftermarket spark plugs.
As odd as this sounds, and I do not have any tech data, we would remove the aftermarkets, both back then and today, and install a set of stock plugs and pretty much all cases no more issues. It had something to do with how the AC Delcos suppress external noise that can get to the alternator and give a false reading though it is charging fine.
Downside, you would not want to run stock plugs in a SC'd car. Upside, if this is actually your issue, then when the message comes up you can tough the reset button and the message goes away. Good thing, at least I have noticed is that there is maybe 1-3% of Vettes that can have this issue.
Hope this helps.
Mike Norris
As odd as this sounds, and I do not have any tech data, we would remove the aftermarkets, both back then and today, and install a set of stock plugs and pretty much all cases no more issues. It had something to do with how the AC Delcos suppress external noise that can get to the alternator and give a false reading though it is charging fine.
Downside, you would not want to run stock plugs in a SC'd car. Upside, if this is actually your issue, then when the message comes up you can tough the reset button and the message goes away. Good thing, at least I have noticed is that there is maybe 1-3% of Vettes that can have this issue.
Hope this helps.
Mike Norris
Melting Slicks
Joined: Jun 2006
Posts: 2,690
Likes: 1
From: Northern Calif
I had this intermittently at idle with the Volts meter showing large swings in voltage levels. I had a tune, headers, FAST, TB, CAI, TR6 plugs.
Tried new alt, tried HO alt(from Rev Extreme--what a POS !)
New battery, raised the idle too. Nothing worked.
Went back to complete stock with a Tech 2 re flash of my entire computer system and all the aforementioned problems are gone. What did the trick? Since the only thing I did not change were the plugs before going back to stock could mean it was the TR6 plugs all along. However, some on this board have the problem with stock plugs so go figure. Maybe tune related in some weird computer glitch sort of way.
Tried new alt, tried HO alt(from Rev Extreme--what a POS !)
New battery, raised the idle too. Nothing worked.
Went back to complete stock with a Tech 2 re flash of my entire computer system and all the aforementioned problems are gone. What did the trick? Since the only thing I did not change were the plugs before going back to stock could mean it was the TR6 plugs all along. However, some on this board have the problem with stock plugs so go figure. Maybe tune related in some weird computer glitch sort of way.
Racer
Joined: Mar 2006
Posts: 281
Likes: 4
From: Houston TX
What we used to find the problem to be when I worked at the dealership of the C5's and today my buddys working on the C6's is aftermarket spark plugs.
As odd as this sounds, and I do not have any tech data, we would remove the aftermarkets, both back then and today, and install a set of stock plugs and pretty much all cases no more issues. It had something to do with how the AC Delcos suppress external noise that can get to the alternator and give a false reading though it is charging fine.
Downside, you would not want to run stock plugs in a SC'd car. Upside, if this is actually your issue, then when the message comes up you can tough the reset button and the message goes away. Good thing, at least I have noticed is that there is maybe 1-3% of Vettes that can have this issue.
Hope this helps.
Mike Norris
As odd as this sounds, and I do not have any tech data, we would remove the aftermarkets, both back then and today, and install a set of stock plugs and pretty much all cases no more issues. It had something to do with how the AC Delcos suppress external noise that can get to the alternator and give a false reading though it is charging fine.
Downside, you would not want to run stock plugs in a SC'd car. Upside, if this is actually your issue, then when the message comes up you can tough the reset button and the message goes away. Good thing, at least I have noticed is that there is maybe 1-3% of Vettes that can have this issue.
Hope this helps.
Mike Norris
Thread Starter
Racer
Joined: Sep 2007
Posts: 357
Likes: 0
What we used to find the problem to be when I worked at the dealership of the C5's and today my buddys working on the C6's is aftermarket spark plugs.
As odd as this sounds, and I do not have any tech data, we would remove the aftermarkets, both back then and today, and install a set of stock plugs and pretty much all cases no more issues. It had something to do with how the AC Delcos suppress external noise that can get to the alternator and give a false reading though it is charging fine.
Downside, you would not want to run stock plugs in a SC'd car. Upside, if this is actually your issue, then when the message comes up you can tough the reset button and the message goes away. Good thing, at least I have noticed is that there is maybe 1-3% of Vettes that can have this issue.
Hope this helps.
Mike Norris
As odd as this sounds, and I do not have any tech data, we would remove the aftermarkets, both back then and today, and install a set of stock plugs and pretty much all cases no more issues. It had something to do with how the AC Delcos suppress external noise that can get to the alternator and give a false reading though it is charging fine.
Downside, you would not want to run stock plugs in a SC'd car. Upside, if this is actually your issue, then when the message comes up you can tough the reset button and the message goes away. Good thing, at least I have noticed is that there is maybe 1-3% of Vettes that can have this issue.
Hope this helps.
Mike Norris
This is valuable info...thanks again!!
JD
Safety Car
Joined: Jan 2006
Posts: 3,598
Likes: 0
From: indianapolis indiana
i got same issue have had it for awhile and replaced battery and alt.... i suspect that there is something like a resistor in the wire coming from the alt that goes bad and then it wont charge past 13.5 volts. i have a new one on the way so we shall see.... but the high out put alt is a joke.....
oh and i have $50 a piece jl audio battery connections so cross that off too
oh and i have $50 a piece jl audio battery connections so cross that off too
