71 Vette was dead today
Thread Starter
Pro
Joined: Nov 2001
Posts: 534
Likes: 6
From: Cave Creek AZ
71 Vette was dead today
Was looking forward to driving the Vette today, had it out last Saturday, no issues. Dead today. Jumped it and got it started, ran for a few minutes thought I was warming it up, then died. Would not restart. Optima battery is a year old, seems to me the alternator stopped generating and the MSD electronic ignition ran the battery out.
Thoughts???
Time for a new alternator? Cannot figure out why it was fine last week and the Alternator would fail so suddenly.
FYI car has a ZZ4 crate motor... all new wiring, etc...
Thoughts???
Time for a new alternator? Cannot figure out why it was fine last week and the Alternator would fail so suddenly.
FYI car has a ZZ4 crate motor... all new wiring, etc...
Last edited by DSchaefe; Dec 4, 2015 at 12:50 PM.
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
Perhaps your alternator was shot last week but as the battery was charged enough you were able to drive it a while.
With the key in the ON position the rear bearing of your alternator should become highly magnetized. If it isn't check to see if both of the side plugin terminals are HOT. If they are the voltage regulator is shot. If the #2 terminal isn't the usual cause is a broken wire just inside of the male blade terminal. If the alternator is operating normally your amp gauge should swing over to 40 amps the moment your engine is started and fast idles.
With the key in the ON position the rear bearing of your alternator should become highly magnetized. If it isn't check to see if both of the side plugin terminals are HOT. If they are the voltage regulator is shot. If the #2 terminal isn't the usual cause is a broken wire just inside of the male blade terminal. If the alternator is operating normally your amp gauge should swing over to 40 amps the moment your engine is started and fast idles.
Thread Starter
Pro
Joined: Nov 2001
Posts: 534
Likes: 6
From: Cave Creek AZ
Perhaps your alternator was shot last week but as the battery was charged enough you were able to drive it a while.
With the key in the ON position the rear bearing of your alternator should become highly magnetized. If it isn't check to see if both of the side plugin terminals are HOT. If they are the voltage regulator is shot. If the #2 terminal isn't the usual cause is a broken wire just inside of the male blade terminal. If the alternator is operating normally your amp gauge should swing over to 40 amps the moment your engine is started and fast idles.
With the key in the ON position the rear bearing of your alternator should become highly magnetized. If it isn't check to see if both of the side plugin terminals are HOT. If they are the voltage regulator is shot. If the #2 terminal isn't the usual cause is a broken wire just inside of the male blade terminal. If the alternator is operating normally your amp gauge should swing over to 40 amps the moment your engine is started and fast idles.
Maybe just an interior light left on all week (door ajar?). Ill keep an eye on it and try to find time to pull the gauge cluster apart again and figure out why it isn't working...
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
It is highly magnetic, but I did discover that my battery gauge is not working no movement at all. I charged the battery, car started and ran. I checked voltage sitting (12.6), idle (13.1) and loaded @ 1500 rpm (14.02) and all appear to be OK.
Maybe just an interior light left on all week (door ajar?). Ill keep an eye on it and try to find time to pull the gauge cluster apart again and figure out why it isn't working...
Maybe just an interior light left on all week (door ajar?). Ill keep an eye on it and try to find time to pull the gauge cluster apart again and figure out why it isn't working...
Yep, it sounds like you did leave an interior light on because it appears your alternator is working just fine. I had several dead batteries because my brake lights were staying on and I didn't know it. The amp gauge in a '71 has a "sensing" wire that is buried in the loom right behind the distributor. I found my wire had pulled out of it's connection and that's why my amp gauge wasn't working. The amp gauge is a necessary gauge that should be working so I suggest you find the cause of it's failure and fix it.
Burning Brakes
Joined: Jul 2015
Posts: 823
Likes: 57
From: Austin TX
My '72 had similar symptoms on two different occasions about a year apart. Both times it was the alternator. The alternator would charge the battery OK with the motor running, but there was an internal leak. It would drain the battery in a day or two if the car wasn't used. After replacing it the second time, I had no more problems for the remaining time I owned the car (three or four years). I seem to remember a mechanic telling me GM had problems with the internal regulator alternators during the first few years.
Last edited by 454Luvr; Dec 4, 2015 at 07:00 PM.
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
If you do not drive the car often you may want to get a trickle charger. I keep one of my vettes on a batteryminder 2012agm. It is a special charger for optima batteries. The charger has even brought back old optima batteries.
Limping across the line
Joined: Oct 2002
Posts: 5,299
Likes: 109
From: Peoria Az
My '72 had similar symptoms on two different occasions about a year apart. Both times it was the alternator. The alternator would charge the battery OK with the motor running, but there was an internal leak. It would drain the battery in a day or two if the car wasn't used. After replacing it the second time, I had no more problems for the remaining time I owned the car (three or four years). I seem to remember a mechanic telling me GM had problems with the internal regulator alternators during the first few years.
You'll have a constant draw when the car is not running.
Thread Starter
Pro
Joined: Nov 2001
Posts: 534
Likes: 6
From: Cave Creek AZ
It is fine now, had it out a few times and it is charging and holding the charge, fires right up each time. So must have been a fluke like a door left ajar that drained the battery.
What made me question that was when I jumped it and got it started, let it run, then disconnected the jumper cables... and after a short while idling it died and the battery was still dead... like the alternator did not charge the battery.
I did notice last night when revving the engine that the instrument lights got noticeably brighter with rpm. So I still have issues to watch and sort out. The optima battery is only a year old so I have trouble believing it is bad...
I'll be using the trickle charger if it is sitting for longer than a day or two.
What made me question that was when I jumped it and got it started, let it run, then disconnected the jumper cables... and after a short while idling it died and the battery was still dead... like the alternator did not charge the battery.
I did notice last night when revving the engine that the instrument lights got noticeably brighter with rpm. So I still have issues to watch and sort out. The optima battery is only a year old so I have trouble believing it is bad...
I'll be using the trickle charger if it is sitting for longer than a day or two.
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Melting Slicks
Joined: Mar 2008
Posts: 2,989
Likes: 198
From: Meriden CT
It is fine now, had it out a few times and it is charging and holding the charge, fires right up each time. So must have been a fluke like a door left ajar that drained the battery.
What made me question that was when I jumped it and got it started, let it run, then disconnected the jumper cables... and after a short while idling it died and the battery was still dead... like the alternator did not charge the battery.
I did notice last night when revving the engine that the instrument lights got noticeably brighter with rpm. So I still have issues to watch and sort out. The optima battery is only a year old so I have trouble believing it is bad...
I'll be using the trickle charger if it is sitting for longer than a day or two.
What made me question that was when I jumped it and got it started, let it run, then disconnected the jumper cables... and after a short while idling it died and the battery was still dead... like the alternator did not charge the battery.
I did notice last night when revving the engine that the instrument lights got noticeably brighter with rpm. So I still have issues to watch and sort out. The optima battery is only a year old so I have trouble believing it is bad...
I'll be using the trickle charger if it is sitting for longer than a day or two.
Burning Brakes
Joined: Jul 2015
Posts: 823
Likes: 57
From: Austin TX
It is fine now, had it out a few times and it is charging and holding the charge, fires right up each time. So must have been a fluke like a door left ajar that drained the battery.
What made me question that was when I jumped it and got it started, let it run, then disconnected the jumper cables... and after a short while idling it died and the battery was still dead... like the alternator did not charge the battery.
I did notice last night when revving the engine that the instrument lights got noticeably brighter with rpm. So I still have issues to watch and sort out. The optima battery is only a year old so I have trouble believing it is bad...
I'll be using the trickle charger if it is sitting for longer than a day or two.
What made me question that was when I jumped it and got it started, let it run, then disconnected the jumper cables... and after a short while idling it died and the battery was still dead... like the alternator did not charge the battery.
I did notice last night when revving the engine that the instrument lights got noticeably brighter with rpm. So I still have issues to watch and sort out. The optima battery is only a year old so I have trouble believing it is bad...
I'll be using the trickle charger if it is sitting for longer than a day or two.
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
You need to fully charge your battery first and then see how well it runs (or doesn't run). As your interior lights get brighter when you rev it the alternator is charging. A 6 amp trickle charger will fully charge the battery in 24 hours so do that before anything else.
We are always here to help so ask any question you want and someone will respond.
We are always here to help so ask any question you want and someone will respond.
Instructor
Joined: Mar 2010
Posts: 155
Likes: 4
From: Florida
Yep, it sounds like you did leave an interior light on because it appears your alternator is working just fine. I had several dead batteries because my brake lights were staying on and I didn't know it. The amp gauge in a '71 has a "sensing" wire that is buried in the loom right behind the distributor. I found my wire had pulled out of it's connection and that's why my amp gauge wasn't working. The amp gauge is a necessary gauge that should be working so I suggest you find the cause of it's failure and fix it.
Can you tell me the color of the "sensing"wire? And the connector it attaches to???
Thank you and sorry to Hijack the thread
Last edited by tmd442; Dec 8, 2015 at 04:27 PM.