C5 Alternator Upgrade - 2001 Automatic
Thread Starter
Heel & Toe
Joined: Feb 2016
Posts: 21
Likes: 1
From: Rancho Cordova, CA
C5 Alternator Upgrade - 2001 Automatic
My 2001 C5 voltage when the car gets hot in hot weather always drop into the 12's and I have went through a couple of batteries of the last year. Plus I have upgraded with a new touch screen stereo, amplifier, and subwoofer and I just replaced another battery as these upgrades just seem to have made things worse, seems like the OEM 110 alternator is not getting the job done. I have been getting a charging fault error message, for sometime before the upgrade, when I start the car.
I have went through several threads here and the suggestions are all over the place. I want to upgrade the alternator with one that will stay at or slightly above 14 when under load. However I have read that a high output Alternator could damage the computer and will give you a charging fault error message as the PCM isn't recognizing the Alternator working.
I wonder if this 145 amp alternator will be any better?
https://www.corvettecentral.com/c5-9...falternator%2f
If anyone knows of a high output alternator that will not give a charging fault error message on the DIC or destroy the computer I am am all ears.
Thanks.
I have went through several threads here and the suggestions are all over the place. I want to upgrade the alternator with one that will stay at or slightly above 14 when under load. However I have read that a high output Alternator could damage the computer and will give you a charging fault error message as the PCM isn't recognizing the Alternator working.
I wonder if this 145 amp alternator will be any better?
https://www.corvettecentral.com/c5-9...falternator%2f
If anyone knows of a high output alternator that will not give a charging fault error message on the DIC or destroy the computer I am am all ears.
Thanks.
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
First, what is the voltage across the battery terminals with the engine running? DIC indicated voltage may not be the same.
Same Q hot?
Are the battery terminals clean and tight -- 11 foot pounds.
Same Q hot?
Are the battery terminals clean and tight -- 11 foot pounds.
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
Race Director
Joined: Oct 2004
Posts: 12,861
Likes: 4,664
I wouldn't want my alternator to be putting a constant 14v into my battery. There's a reason we have voltage regulators. A constant 14v will assassinate the battery in probably the same time frame, or less, than you're seeing now. I'm wondering if your voltage regulator isnt doing that right now? As jim993 said, check voltage at the terminals. IIRC, the DIC will provide a lower reading than across the terminals will, because it goes thru the ignition switch. Which may, or may not, have good terminals/connections. My .02.....
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
You can use any alternator that fits but then you're looking at possible tuning or even wiring changes
The 01 up alternators are supposedly not drop in replacements for the earlier one. The regulator is different.
All alternators are set to regulate around 14V, typically 14.2V but it can vary with temperature and application a bit. Newer cars let the voltage drop and then charge again for efficiency reasons, not battery life.
The 01 up alternators are supposedly not drop in replacements for the earlier one. The regulator is different.
All alternators are set to regulate around 14V, typically 14.2V but it can vary with temperature and application a bit. Newer cars let the voltage drop and then charge again for efficiency reasons, not battery life.
Le Mans Master
Joined: Feb 2007
Posts: 9,294
Likes: 1,527
From: Oviedo Florida
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My 2000 was raced for years and I put a bigger alt. on.
Check with Quality Power.
Check with Quality Power.
Thread Starter
Heel & Toe
Joined: Feb 2016
Posts: 21
Likes: 1
From: Rancho Cordova, CA
Good news, I have found a very good alternator for my 2001 C5 that doesn't throw an error message on the DIC like other high output alternators.
https://www.dbelectrical.com/product...1-ava0008.html
This is a 145 amp 12 volt alternator and has been every good so far staying between a charge of 14 to 14.3.
https://www.dbelectrical.com/product...1-ava0008.html
This is a 145 amp 12 volt alternator and has been every good so far staying between a charge of 14 to 14.3.
Last edited by FreedomFighter; Apr 2, 2024 at 06:47 PM. Reason: Wrong word
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Drifting
Joined: Jan 2015
Posts: 1,256
Likes: 157
From: Pennsylvania
You should be getting 13.8/14.2v at the battery when engine is running at all times. If you are getting less it is one of 2 things a bad alternator or bad wiring. Being that you have determined that it is temperature sensitive I would lean to the alternator being bad but would need to do some more checking to 100% know.
If it was mine I would be replacing the alternator and doing a big 3 upgrade. Adding a higher amp alt is beneficial but not necessary for the amount of draw your electrical system is making.
If it was mine I would be replacing the alternator and doing a big 3 upgrade. Adding a higher amp alt is beneficial but not necessary for the amount of draw your electrical system is making.