Alternator question
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Jun 4, 2019, 12:48 PM
Pro
Joined: Jan 2016
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From: Sandown NH
An alternator only puts out what the demand of the car is. Unless you have added some high power sound system or other high current draw equipment that exceeds the stock current rating, a larger current capacity alternator will do nothing for you and is simply not needed.
Drifting
Joined: Sep 2006
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I just changed my alternator to the 145 amp. I have an early 2003 and it had the 110 amp, after my car died on the side of the road for electrical issues, I felt a higher amp alternator was in order. I have a manual car but I'm sure the 145 is fine for the automatic too.
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From: Oviedo Florida
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The older these vettes get , you start to lose amps.
I run a 200 amp with no problems.
I run a 200 amp with no problems.
Thread Starter
Racer
Joined: Mar 2019
Posts: 302
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From: Northern NV
I just changed my alternator to the 145 amp. I have an early 2003 and it had the 110 amp, after my car died on the side of the road for electrical issues, I felt a higher amp alternator was in order. I have a manual car but I'm sure the 145 is fine for the automatic too.
do you have do do anything with fuses because of the higher amps?
Pro
Joined: Jan 2016
Posts: 524
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From: Sandown NH
An alternator only puts out what the demand of the car is. Unless you have added some high power sound system or other high current draw equipment that exceeds the stock current rating, a larger current capacity alternator will do nothing for you and is simply not needed.
Last edited by v6turbo87; Jun 4, 2019 at 12:49 PM.
Drifting
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Instructor
Joined: Mar 2008
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Have you had any issues after upgrading to the 145amp?
Did you use the model with the clutch pulley on your manual c5?
Any issues with the clutch pulley on a manual transmission?
My 1999 manual has a 110amp and thinking of upgrading to the 145amp, if it works on the 1999.
Did you use the model with the clutch pulley on your manual c5?
Any issues with the clutch pulley on a manual transmission?
My 1999 manual has a 110amp and thinking of upgrading to the 145amp, if it works on the 1999.
Instructor
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Originally Posted by Jeffreydd;[url=tel:1606578243
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Instructor
Joined: Mar 2008
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Originally Posted by Jeffreydd;[url=tel:1606578455
1606578455[/url]]Why do you need the extra amps? Aftermarket stereo?
The reason I need a replacement is one of the brushes broke. An alternator rebuilder suggested a $30 rebuild kit or replacing with the 145amp version.
Original 24 year old Valeo alternator with 65k miles, is it worth rebuilding? New is ~$350+
Instructor
Joined: Mar 2008
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Based on advice from the forum members I went with AC Delco reman 110amp for $200 shipped from Amazon.
I really don’t need the extra amps, no need to introduce other issues.
thanks all
I really don’t need the extra amps, no need to introduce other issues.
thanks all
Instructor
Joined: Sep 2008
Posts: 155
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From: Plano TX
Remember V=IR. If the voltage across the battery and the resistance stays the same, the current in your circuit stays the same regardless of the alternator current rating. The only way it will go up is if your voltage regulator fails.
Instructor
Joined: Aug 2022
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From: Ashburn, VA
I'd stick with 110amps unless you plan on adding a Amp/Sub combo and additional power ****** that need the amps. Just responded to another fellas thread about IPC messages about "Charging System faults" with an HO alternator. As the fella above noted...the VR is gonna command the alternator to put out what the car needs...and nothing more [up to capacity]. Whats the point of a 145 Amp alternator if the cars only commanding 90 taxed out with everything on. Save the money and buy beer 
Instructor
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Originally Posted by averagejoesautos;[url=tel:1606595838
1606595838[/url]]I'd stick with 110amps unless you plan on adding a Amp/Sub combo and additional power ****** that need the amps. Just responded to another fellas thread about IPC messages about "Charging System faults" with an HO alternator. As the fella above noted...the VR is gonna command the alternator to put out what the car needs...and nothing more [up to capacity]. Whats the point of a 145 Amp alternator if the cars only commanding 90 taxed out with everything on. Save the money and buy beer