In need of some alternator advice - Page 2 - CorvetteForum - Chevrolet Corvette Forum Discussion



C6 Corvette General Discussion
General C6 Corvette Discussion not covered in Tech
Sponsored by:
Sponsored by:

In need of some alternator advice

Reply
 
 
 
Thread Tools Search this Thread
Old 07-15-2017, 02:59 PM   #21
Dano523
CF Senior Member
 
Member Since: Dec 2013
Posts: 4,467
Thanks: 0
Thanked 379 Times in 304 Posts
Default

Quote:
Originally Posted by Corvette_Ed View Post
The thing that had me concerned is the 13.4 wasn't a fluke. I was running at 13.4-13.8 consistently while cruising at highway speeds (70-80 mph) during the day in triple digit temps. I was just out for a drive trying to find a shop to do a load test, and I was seeing it drop down to as low as 12.6 at a steady 45 mph @ close to 2k rpm. Unfortunately, it looks like I'm going to have to wait until next week when I can get by my buddy's shop after work to have it load tested.
If it was a cracked wire winding in the alternator, then the problem does not self correct.

With the amount of heat, still say to clean up the OEM before you replace it, and go through the charging wiring system connectors to make sure that it was not heat induced connector problem.

Hell who knows, and may find that the problem is just a cracked bakelite starter solenoid cap/terminal problem that was causing the problem in the high heat, and just need to replace the starter solenoid isntead.



New starter solenoid for $25
https://www.amazon.com/Premium-Quali...iglink20400-20

Last edited by Dano523; 07-15-2017 at 03:01 PM.
Dano523 is online now   Reply With Quote
Old 07-15-2017, 03:21 PM   #22
Corvette_Ed
CF Senior Member
Thread Starter
 
Corvette_Ed's Avatar
 
Member Since: May 2012
Location: Dallas/Ft. Worth
Posts: 9,332
Thanked 399 Times in 312 Posts
Default

Quote:
Originally Posted by Dano523 View Post
If it was a cracked wire winding in the alternator, then the problem does not self correct.

With the amount of heat, still say to clean up the OEM before you replace it, and go through the charging wiring system connectors to make sure that it was not heat induced connector problem.

Hell who knows, and may find that the problem is just a cracked bakelite starter solenoid cap/terminal problem that was causing the problem in the high heat, and just need to replace the starter solenoid isntead.



New starter solenoid for $25
https://www.amazon.com/Premium-Quali...iglink20400-20
That does make sense, and this is some good advice. Guess I'll plan on spending time under the hood next weekend cleaning the connections and inspecting the starter solenoid. I'm prepared to spend the money on a new alternator if I have to, but I'd really prefer not to, which is why I decided to ask here before throwing money at the problem. I'll post an update next week after I finish.

I appreciate everyone's help with this.
Corvette_Ed is offline   Reply With Quote
Old 07-15-2017, 03:39 PM   #23
Bruze
CF Senior Member
 
Bruze's Avatar
 
Member Since: Mar 2014
Location: Western NYS
Posts: 4,581
Thanked 307 Times in 252 Posts
Default

Good luck Ed. Interesting thread.
Bruze is online now   Reply With Quote
Old 07-15-2017, 05:55 PM   #24
Corvette_Ed
CF Senior Member
Thread Starter
 
Corvette_Ed's Avatar
 
Member Since: May 2012
Location: Dallas/Ft. Worth
Posts: 9,332
Thanked 399 Times in 312 Posts
Default

Quote:
Originally Posted by Bruze View Post
Good luck Ed. Interesting thread.
Thanks Bruze.

Looks like I have some work to do to resolve this, but if it saves me $500+ it's worth it.
Corvette_Ed is offline   Reply With Quote
Old 07-15-2017, 06:00 PM   #25
wayback
CF Senior Member
 
wayback's Avatar
 
Member Since: Aug 2006
Location: Mansfield TEXAS
Posts: 13,138
Thanked 412 Times in 345 Posts
Default

Just about all auto parts stores can test your Alt and battery, on or off the car. Results can be mixed, I went to 3 that were in the same block....1 said Alt was in working order, 2 said it failed their test.
wayback is online now   Reply With Quote
Old 07-16-2017, 07:23 AM   #26
PCMusicGuy
CF Senior Member
 
Member Since: Apr 2007
Location: Houston TX
Posts: 2,729
Thanked 19 Times in 18 Posts
Default

I have over 130k miles on my original alternator and my car, an 07 completely stock, exhibits the symptoms yours does on occasion when really hot.

I don't think what you are experiencing is unusual with your combination of aftermarket audio/heat. I wouldn't worry about it until it actually failed.
PCMusicGuy is online now   Reply With Quote
Old 07-16-2017, 12:29 PM   #27
Dano523
CF Senior Member
 
Member Since: Dec 2013
Posts: 4,467
Thanks: 0
Thanked 379 Times in 304 Posts
Default

Quote:
Originally Posted by PCMusicGuy View Post
I have over 130k miles on my original alternator and my car, an 07 completely stock, exhibits the symptoms yours does on occasion when really hot.

I don't think what you are experiencing is unusual with your combination of aftermarket audio/heat. I wouldn't worry about it until it actually failed.
Would take the 20 mins to pull the alternator, pull it apart to clean up it and in contact points up, as well as may just change out the brushes while you have it open as well.

The brushes are less than $10, and only take a min to re-solder the new ones back into the old brush housing.
Dano523 is online now   Reply With Quote
Old 07-16-2017, 12:49 PM   #28
LowRyter
CF Senior Member
 
LowRyter's Avatar
 
Member Since: Feb 2016
Location: Edmond Oklahoma
Posts: 715
Thanked 53 Times in 42 Posts
Default

Quote:
Originally Posted by Corvette_Ed View Post
Battery tested just fine, and as I mentioned, the system appears to work normally when temps are in the 80-90 range. It's the triple digit temps that seem to be the primary cause. I do plan on load testing the system before I make a final decision, though.
perhaps so. So if the battery checked good, did the alternator check bad? Yep, it's really hot and that kills batteries.

I've been bothered by Evap codes and TPMS codes for nearly a year. After I changed battery the (Evap) engine light turned itself off. I have to wonder if those TPMS sensors were bad?

A new battery is $120. Cheap.
LowRyter is offline   Reply With Quote
Old 07-16-2017, 02:09 PM   #29
Mad*Max
CF Senior Member
 
Mad*Max's Avatar
 
Member Since: Apr 2007
Location: Toronto, Canada
Posts: 13,110
Thanked 72 Times in 68 Posts
Default

sounds okay to me - with the a/c on the engine fan draws a lot of power - mine probably runs the same as far as I can remember
Mad*Max is offline   Reply With Quote
Old 07-17-2017, 06:59 AM   #30
Corvette_Ed
CF Senior Member
Thread Starter
 
Corvette_Ed's Avatar
 
Member Since: May 2012
Location: Dallas/Ft. Worth
Posts: 9,332
Thanked 399 Times in 312 Posts
Default

Quote:
Originally Posted by LowRyter View Post
perhaps so. So if the battery checked good, did the alternator check bad? Yep, it's really hot and that kills batteries.

I've been bothered by Evap codes and TPMS codes for nearly a year. After I changed battery the (Evap) engine light turned itself off. I have to wonder if those TPMS sensors were bad?

A new battery is $120. Cheap.
My battery is new. Just bought it a few months ago.
Corvette_Ed is offline   Reply With Quote
Old 07-17-2017, 07:44 AM   #31
RobLo
CF Senior Member
Support Corvetteforum!
 
RobLo's Avatar
 
Member Since: May 2010
Location: Long Island New York
Posts: 1,282
Thanked 39 Times in 32 Posts
Default

'05 A4 Z51 with 31K miles, I've had similar issues with low voltage showing on the DIC. First thing, listen to Dano, he one of the smartest guys on here when it comes to charging systems, electrical and is always willing to help with good advice. I've had times when, sitting in heat with everything going the DIC showed 11.5-12 at idle, drove my crazy. I haven't had the time to go through the car and clean all the grounds as Dano suggests but I did have my alternator checked recently at a reputable repair/rebuild shop and all is good, the shop owner said it was working just like it was supposed to, he said these alternators are usually good for at least 75K miles. I also explained my (your, our) issue to my mechanic, a VERY well respected Vette guy in this area and he said the same thing, this is completely normal for our cars, just a quirk of the C6's. Until something drastic happens I'm gonna clean the connections and leave it alone...good luck!
RobLo is offline   Reply With Quote
Old 07-17-2017, 09:25 AM   #32
Corvette_Ed
CF Senior Member
Thread Starter
 
Corvette_Ed's Avatar
 
Member Since: May 2012
Location: Dallas/Ft. Worth
Posts: 9,332
Thanked 399 Times in 312 Posts
Default

Quote:
Originally Posted by RobLo View Post
'05 A4 Z51 with 31K miles, I've had similar issues with low voltage showing on the DIC. First thing, listen to Dano, he one of the smartest guys on here when it comes to charging systems, electrical and is always willing to help with good advice. I've had times when, sitting in heat with everything going the DIC showed 11.5-12 at idle, drove my crazy. I haven't had the time to go through the car and clean all the grounds as Dano suggests but I did have my alternator checked recently at a reputable repair/rebuild shop and all is good, the shop owner said it was working just like it was supposed to, he said these alternators are usually good for at least 75K miles. I also explained my (your, our) issue to my mechanic, a VERY well respected Vette guy in this area and he said the same thing, this is completely normal for our cars, just a quirk of the C6's. Until something drastic happens I'm gonna clean the connections and leave it alone...good luck!
I'd already planned on following Dano's advice and cleaning all of the connections this coming weekend. I'd have done it this past weekend, but needed to clean up the aftermath of my vert's first time driving in the rain. Got stuck in an unexpected rain storm Friday on my way home. First time I've used my windshield wipers.
Corvette_Ed is offline   Reply With Quote
Old 07-17-2017, 10:49 AM   #33
unixcorn
CF Senior Member
Support Corvetteforum!
 
unixcorn's Avatar
 
Member Since: Oct 2010
Location: Rocheport Missouri
Posts: 1,497
Thanked 74 Times in 64 Posts
Default

Quote:
Originally Posted by 2L8LUZ View Post
Do you have a capacitor in-line for your amp??? This will make a BIG difference here and the amp will draw power from the capacitor vs the battery
This isn't exactly true. While it really is unrelated to this topic, I need to clarify this because it bugs me. An audio amplifier is a live load. In other words, it's current draw isn't constant. In the case of a hard hitting, low frequency amp, even more so.

What a capacitor will do for the amp is provide momentary spikes of current during the highest load times. The internal resistance of a capacitor, local to the amplifier, is much lower than the battery's and so it, along with a diode, can provide a much more stable voltage to the amp if the cap is sized correctly AND the power supply (in this case the battery and alternator) can supply enough current, on average, to keep the cap charged.

If the alternator and battery are weak or other appliances are drawing more current than the alternator can provide, the battery does it's best to make up the current at the cost of voltage dropping. Age, heat and load all play a part in how much current a battery can deliver. The battery's other responsibility, to smooth the pulsating DC from the alternator can also play a factor, especially if one of the diodes in the alternator is weak and compounding the issue.

My point to all of this is that a capacitor, while an appropriate part of an audio system to bolster sound quality, won't band-aid a failing charging system. Without adequate current from the alternator/battery the cap eventually becomes ineffective. There is no free lunch when it comes to electronics.
unixcorn is online now   Reply With Quote
Old 07-17-2017, 11:11 AM   #34
Bruze
CF Senior Member
 
Bruze's Avatar
 
Member Since: Mar 2014
Location: Western NYS
Posts: 4,581
Thanked 307 Times in 252 Posts
Default

Quote:
Originally Posted by RobLo View Post
'05 A4 Z51 with 31K miles, I've had similar issues with low voltage showing on the DIC. First thing, listen to Dano, he one of the smartest guys on here when it comes to charging systems, electrical and is always willing to help with good advice. I've had times when, sitting in heat with everything going the DIC showed 11.5-12 at idle, drove my crazy. I haven't had the time to go through the car and clean all the grounds as Dano suggests but I did have my alternator checked recently at a reputable repair/rebuild shop and all is good, the shop owner said it was working just like it was supposed to, he said these alternators are usually good for at least 75K miles. I also explained my (your, our) issue to my mechanic, a VERY well respected Vette guy in this area and he said the same thing, this is completely normal for our cars, just a quirk of the C6's. Until something drastic happens I'm gonna clean the connections and leave it alone...good luck!
I agree, showing 11.5 - 12 at idle with AC and everything else running shouldn't be alarming.

From days of yore: One reason they switched from generators to alternators is that generators would not produce enough current at idle, and the GEN idiot light would flicker -- meaning it was drawing some power from the battery also, because the generator couldn't keep up.

Alternators eliminated that. However, with AC being on nearly every car now, along with high current-drawing sound systems and other accessories that didn't used to exist, sometimes alternator output is marginal. So in extreme conditions, apparently it will draw some current from the battery.

If that's what it is, and I have this right, then it isn't anything to worry about (we wouldn't even know about it except for the DIC staring us in the face, tempting us to press the button ).

The battery is being used a bit more than it would be otherwise, but assuming everything else is up to snuff (alt output, ground connections) once you're off idle for a while it should charge back up to normal.

[love-hate] DIC [/love-hate]
Bruze is online now   Reply With Quote
Old 07-17-2017, 05:11 PM   #35
AORoads
CF Senior Member
St. Jude Donor '15
"In honor of jpee"
 
AORoads's Avatar
 
Member Since: Jun 2005
Location: Northern, VA
Posts: 40,854
Thanked 663 Times in 559 Posts
Default

Quote:
Originally Posted by unixcorn View Post
This isn't exactly true. While it really is unrelated to this topic, I need to clarify this because it bugs me. An audio amplifier is a live load. In other words, it's current draw isn't constant. In the case of a hard hitting, low frequency amp, even more so.

What a capacitor will do for the amp is provide momentary spikes of current during the highest load times. The internal resistance of a capacitor, local to the amplifier, is much lower than the battery's and so it, along with a diode, can provide a much more stable voltage to the amp if the cap is sized correctly AND the power supply (in this case the battery and alternator) can supply enough current, on average, to keep the cap charged.

If the alternator and battery are weak or other appliances are drawing more current than the alternator can provide, the battery does it's best to make up the current at the cost of voltage dropping. Age, heat and load all play a part in how much current a battery can deliver. The battery's other responsibility, to smooth the pulsating DC from the alternator can also play a factor, especially if one of the diodes in the alternator is weak and compounding the issue.

My point to all of this is that a capacitor, while an appropriate part of an audio system to bolster sound quality, won't band-aid a failing charging system. Without adequate current from the alternator/battery the cap eventually becomes ineffective. There is no free lunch when it comes to electronics.
I read thru the entire thread and this post and sentence jogged my memory. From way long ago, some of you will remember Paul "talon90". He told me that the C6 was designed to be as light as possible and that meant a lot of components and systems were the opposite of "maximized"---meaning, they were minimized. One of them was the under-hood, charging/starting system to save weight. This would include the batt., alternator, starter, etc. I think many have suffered with batts. that go dead after a few weeks (many/most don't, but my 3 mos. old NCM-delivery did so in my garage w/o a tender).

So, take it for what it's worth and this is an excellent thread w. comments from all and Dano.

Good luck Corv. Ed.
AORoads is offline   Reply With Quote
Old 07-17-2017, 10:00 PM   #36
719c6
CF Member
 
719c6's Avatar
 
Member Since: Jul 2014
Location: New Haven MO
Posts: 92
Thanked 2 Times in 2 Posts
Default

Quote:
Originally Posted by Dano523 View Post
Would take the 20 mins to pull the alternator, pull it apart to clean up it and in contact points up, as well as may just change out the brushes while you have it open as well.

The brushes are less than $10, and only take a min to re-solder the new ones back into the old brush housing.
Have a part # for the brushes?
719c6 is offline   Reply With Quote
Old 07-20-2017, 07:00 AM   #37
Corvette_Ed
CF Senior Member
Thread Starter
 
Corvette_Ed's Avatar
 
Member Since: May 2012
Location: Dallas/Ft. Worth
Posts: 9,332
Thanked 399 Times in 312 Posts
Default

I drove into work again today. With A/C on and radio blasting it was running 14.0-14.2 at highway speeds at just over 80 degrees. At stoplights the lowest it dropped to was 13.4. I'll keep an eye on it on the way home today as it will be triple digit temps with the heat index, but it's definitely looking like heat is my problem, and that the system itself is working just fine. I still plan on cleaning all of the connections this weekend, though, as I'm sure there's some oxidization of the metal and I want to see what the starter solenoid looks like.
Corvette_Ed is offline   Reply With Quote
Old 07-20-2017, 08:14 AM   #38
wayback
CF Senior Member
 
wayback's Avatar
 
Member Since: Aug 2006
Location: Mansfield TEXAS
Posts: 13,138
Thanked 412 Times in 345 Posts
Default

Like AORoads said GM designed and built the charging system to just cover the cars needs in normal conditions (and as cheaply as they could).

The Mechman alt produces 14.6 v at idle with max load even in out N. Texas summers. Great upgrade as everything runs better with stable voltage.
wayback is online now   Reply With Quote
Old 07-20-2017, 08:58 AM   #39
Corvette_Ed
CF Senior Member
Thread Starter
 
Corvette_Ed's Avatar
 
Member Since: May 2012
Location: Dallas/Ft. Worth
Posts: 9,332
Thanked 399 Times in 312 Posts
Default

Quote:
Originally Posted by wayback View Post
Like AORoads said GM designed and built the charging system to just cover the cars needs in normal conditions (and as cheaply as they could).

The Mechman alt produces 14.6 v at idle with max load even in out N. Texas summers. Great upgrade as everything runs better with stable voltage.
The whole point of this thread was to determine whether or not I really need a new alternator, and how to avoid having to purchase one if possible.
Corvette_Ed is offline   Reply With Quote
Old 07-20-2017, 10:05 PM   #40
Roblutts
Junior Member
 
Roblutts's Avatar
 
Member Since: Dec 2016
Location: Plano Texas
Posts: 34
Thanked 1 Time in 1 Post
Default

Quote:
Originally Posted by Corvette_Ed View Post
The whole point of this thread was to determine whether or not I really need a new alternator, and how to avoid having to purchase one if possible.
Corvette_Ed,

I'm in Plano, so in your neck of the woods. I've had my '07 Vert for a couple of months now, and mine behaves exactly like yours. I did lots of research on this on here and the web and I was fully prepared to buy a new aftermarket alternator just to avoid any headaches, but it seems like this is all normal. An electrical engineer (claimed to be) on another site said that it's normal for the car to show 14.2-14.4 on start up for a few and then eventually drop down a little as the car warms and the battery charges. The Texas heat does take a toll on our batteries for sure. I don't daily drive mine, but make sure to drive it at least a couple times a week, just to make sure it's getting some charge, fluids are flowing etc. I'm also one of the OCD drivers that opens the hood once parked in the garage to let it cool off faster. At least it does in my mind! Lol! I did notice that the alternator stays hot way after the rest of the engine has cooled down. Anyway, I'm going to stay with mine for now and try not to OCD on it too much!
Roblutts is offline   Reply With Quote
Go Back   CorvetteForum - Chevrolet Corvette Forum Discussion >
Reload this Page
  • In need of some alternator advice
  •  
     
    Reply

    Related Topics
    Thread Thread Starter Forum Replies Last Post
    alternator? popshumphrey C5 Tech 23 10-09-2015 01:44 PM
    Billet Tech alternator Group Buy is here! [email protected] C5 General 92 02-15-2014 11:21 AM
    Billet Tech Alternator sale is on! [email protected] C5 Vendor for Sale 18 11-22-2013 04:13 PM
    Billet Tech alternator Group Buy is here! [email protected] C6 Parts for Sale/Wanted 78 11-22-2013 04:10 PM
    Alternator Output Voltage? 97C5ENVY C5 Tech 4 09-30-2011 07:23 PM


    Thread Tools Search this Thread
    Search this Thread:

    Click for Advanced Search

    Posting Rules
    You may not post new threads
    You may not post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are Off
    Pingbacks are Off
    Refbacks are Off

    Forum Jump


    All times are GMT -4. The time now is 02:52 PM.


     
    • Ask a Question
      Get answers from community experts
    Question Title:
    Description:
    Your question will be posted in: