Alternator going bad? - ZR-1 Net Registry Forums

-=Jeff=- · 04-18-2014

What are some of the signs?

I noticed today when I get on it at about the 5K RPM the voltage meter on the dash starts to drop (enough to see it move) not sure what voltage it drops to..

otherwise all seems fine.. Do I need to get a replacement again?

LGAFF · 04-18-2014

volts being all over is a definite sign its going, check your batter terminals first make sure its tight

LGAFF · 04-18-2014

or might be all of the high tech gadgets you are running in your car zapping the power

-=Jeff=- · 04-18-2014

Sure if it all over the place, but the Needle stay put until the RPMs climb past 4K, then the voltages fall, as soon as the RPMs drop it is fine.. I doubt the 12-5v ps I added is causing the issue.. Many people are using it.. Guess I will buy an Alternator to be safe

LantanaTX · 04-18-2014

Quote:

Originally Posted by -=Jeff=-

Sure if it all over the place, but the Needle stay put until the RPMs climb past 4K, then the voltages fall, as soon as the RPMs drop it is fine.. I doubt the 12-5v ps I added is causing the issue.. Many people are using it.. Guess I will buy an Alternator to be safe

Most parts stores will check the charging system for free and put a load on it. I would do this before just throwing money at it.

-=Jeff=- · 04-18-2014

Quote:

Originally Posted by LantanaTX

Most parts stores will check the charging system for free and put a load on it. I would do this before just throwing money at it.

Yeah but having a spare is always a good thing.. might buy a higher output one that was shown on here awhile back

Blue Flame Restorations · 04-18-2014

When mine went out of my 9500, 95, the battery light came on the display eventually.

Evidently, the car had not had a battery tender on it for some time. It does now, always.

WVZR-1 · 04-18-2014

Quote:

Originally Posted by -=Jeff=-

What are some of the signs?

I noticed today when I get on it at about the 5K RPM the voltage meter on the dash starts to drop (enough to see it move) not sure what voltage it drops to..

otherwise all seems fine.. Do I need to get a replacement again?

You want to check the complete electrical "on the car" using a "Carbon Pile" load tester and a DMM. That's the only way to actually evaluate the system and it should be done before doing any alternator/generator OR starter replacement.

-=Jeff=- · 04-18-2014

OK, get down to 11 volts when at 5k rpm

Below that rpm it is high 12s, I will data log to a file next time

scottfab · 04-19-2014

Quote:

Originally Posted by -=Jeff=-

OK, get down to 11 volts when at 5k rpm

Below that rpm it is high 12s, I will data log to a file next time

Battery V should be at 14.5v or so at idle if alternator is doing it's thing.

04-18-2014	#1
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,169	Alternator going bad? What are some of the signs? I noticed today when I get on it at about the 5K RPM the voltage meter on the dash starts to drop (enough to see it move) not sure what voltage it drops to.. otherwise all seems fine.. Do I need to get a replacement again? __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

04-18-2014	#2
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Alternator going bad? volts being all over is a definite sign its going, check your batter terminals first make sure its tight __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

04-18-2014	#3
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Alternator going bad? or might be all of the high tech gadgets you are running in your car zapping the power __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

04-18-2014	#4
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,169	Re: Alternator going bad? Sure if it all over the place, but the Needle stay put until the RPMs climb past 4K, then the voltages fall, as soon as the RPMs drop it is fine.. I doubt the 12-5v ps I added is causing the issue.. Many people are using it.. Guess I will buy an Alternator to be safe __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 Last edited by -=Jeff=-; 04-18-2014 at 04:17 PM.

04-18-2014	#7
Blue Flame Restorations Join Date: Feb 2010 Location: Pendleton, IN Posts: 3,904	Re: Alternator going bad? When mine went out of my 9500, 95, the battery light came on the display eventually. Evidently, the car had not had a battery tender on it for some time. It does now, always. __________________ 1988 KOH Prototype EX5023 sold 1990 ZR-1 #444 Convertible 1990 ZR-1 Black #966 1991 ZR-1 Quazar Blue #296 1957 Duntov SS Project

04-18-2014	#9
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,169	Re: Alternator going bad? OK, get down to 11 volts when at 5k rpm Below that rpm it is high 12s, I will data log to a file next time __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978