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Discussion Starter · #1 ·
It would appear I am at an impass. When I bought my Nova the battery kept draining down and dying which made me think I had a short. Therefore I installed a new battery with quick disconnect on the ground terminal, but it kept happening. I had the alternator (a 1-wire) tested while in the car and even running the car was only at 12 volts so the alternator was not charging the battery. I have now replaced the alternator (another 1-wire) and the wiring from alternator to battery with new 10-gauge. However I am still only getting between 11 and 12 volts when running. What else could it be?????

Here are the new parts again:
Duralast Gold Battery
1-Wire Alternator
10-gauge wiring, Alternator to Battery Terminal

I dont know of any other parts within this system that could be failing and causing this issue :mad:
 

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It's possible that the alternator isn't running in it's energized charging mode at the RPM you're testing it at.

Some alternators require that the engine RPMs be blipped past a certain RPM in order to engage its energizing circuits. Yours may be one of these.
 

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It's possible that the alternator isn't running in it's energized charging mode at the RPM you're testing it at.

Some alternators require that the engine RPMs be blipped past a certain RPM in order to engage its energizing circuits. Yours may be one of these.
:yes::yes:



One other thing to keep in mind with these 1 wire alternator's.

The last one I bought wouldn't charge, even after a couple of 2500 rpm blips it still wouldn't charge. I took the alternator to a alternator and starter repair shop. After a quick check on the machine the guy said it was bad. I said o.k. I'll just return it. He then asked "is this brand new", I told him :yes::yes:

He say's hang on a minute, took it back over to the machine excited the regulator and waaala, it worked.

It seems that during the manufacturing process the regulator need's to be "excited", mine wasn't. The guy told me he it doesn't happen very often but he has seen enough of them to check it on new alternators when they're not working.
 

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Check your voltage right at the altenator lug. If it is 12 volts there, then I would suspect the altenator. If it 14 volts there, your issue is down stream.
 

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Discussion Starter · #5 ·
Thanks for the feedback everyone!!

As far as running it at a higher rpm I have revved it up to about 3k rpms before testing which should have "excited" it into activation. However I have not tried to test it while being revved up. Would it only put out the 14 volts while revving?

Also klean63 was that a one time thing or did he say it would need to be "excited" every time the car was started?

And is it possible to start and run the car without the alternator to battery cable being hooked up so its just running off the battery? I think that would be the best way to test right at the battery output terminal of the alternator so I didnt have power coming from the batter if the alternator was bad.
 

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Thanks for the feedback everyone!!

As far as running it at a higher rpm I have revved it up to about 3k rpms before testing which should have "excited" it into activation. However I have not tried to test it while being revved up. Would it only put out the 14 volts while revving?

Also klean63 was that a one time thing or did he say it would need to be "excited" every time the car was started?

And is it possible to start and run the car without the alternator to battery cable being hooked up so its just running off the battery? I think that would be the best way to test right at the battery output terminal of the alternator so I didnt have power coming from the batter if the alternator was bad.
It is possible the altenator can't keep up with our load at an idle which would cause the voltage to be low at idle.

Check you voltage at 3000 RPM and check your voltage at the post on the altenator. to rule out a problem in the wiring down stream.

You can run the car without the altenator hooked up, but the altenator will not work if it doesn't have current from the battery to start it. Once you get the car started, rev it to 3000 RPM to make sure the altenator is working, then unhook the battery.
 

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Discussion Starter · #7 ·
So I should have stated also that I tried to "have it running and disconnect the positive battery terminal" method and the car died immediately so the alternator is not putting out enough to hold the car running. Also I have been testing directly at the alternator output post and am still getting 10.5-11.5 volts.

I have not yet tested while holding the car at 3000rpms but I will do that tomorrow. I guess its possible that I got another bum alternator :(

Is everyone running the standard Delco alternators or have you upgraded to like a Bosch or Powermaster? If so could you give me part numbers?
 

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wow are you sure you dont have my nova? :D
i have the same exact problem and i dont know what the heck is causing it..same thing as yours my battery keeps on draining when my car is off so it wont start but yesteday i had my friend jump me, took sometime and she had just enough juice to start well i let her run for about 20 mins to see if the battery would charge and then i turned it off to try and start it again and nothing it was like there was never any juice to begin with she wouldnt even turn over...is this the same problem?
 

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Discussion Starter · #9 ·
wow are you sure you dont have my nova? :D
i have the same exact problem and i dont know what the heck is causing it..same thing as yours my battery keeps on draining when my car is off so it wont start but yesteday i had my friend jump me, took sometime and she had just enough juice to start well i let her run for about 20 mins to see if the battery would charge and then i turned it off to try and start it again and nothing it was like there was never any juice to begin with she wouldnt even turn over...is this the same problem?
Yeah mine is the same. I have a battery charger at home so I charge the battery back up and it lasts for a few days of starting just to move her in and out of garage but then is drained, even with quick disconnect when she sits. :mad:

I did however test the alternator only, without the alternator to battery cable hooked up and voltmeter read 0 volts so I think my "new" alternator may be bad. I am going to go exchange it today and have them test it before I even leave the store to see if it makes a difference. Thank goodness its outrageously easy to pull that thing off and put back on or else this would be a real pain!!
 

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Yeah mine is the same. I have a battery charger at home so I charge the battery back up and it lasts for a few days of starting just to move her in and out of garage but then is drained, even with quick disconnect when she sits. :mad:

I did however test the alternator only, without the alternator to battery cable hooked up and voltmeter read 0 volts so I think my "new" alternator may be bad. I am going to go exchange it today and have them test it before I even leave the store to see if it makes a difference. Thank goodness its outrageously easy to pull that thing off and put back on or else this would be a real pain!!
mmm i might try that cause its a real pain in the ace but i think i should get my alternator tested as well. so we will see whats going on with our nova's :D let me know how it goes man!
 

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Just because it is new doesn't mean it works. Also, make sure it doesn't say "Made in China."
 

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Also klean63 was that a one time thing or did he say it would need to be "excited" every time the car was started?
It's a one time thing, it's kinda like the regulator left the factory "locked".

Once it was "un-locked" all was good. Don't be to proud to take it to a good alternator shop to have it checked (not Pep Boys, Autozone...)
 

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Do you have the correct alternator?

Hello. In 1969 Chevrolet used alternators with the external regulator. Around 1973 or so they started using alternators with the self contained regulator. The one wire system uses the self regulated alternator. Your NOVA is probably wired for the external regulator. A fairly simple wiring modification is all that is needed to run a self regulating alternator.

This may be your problem. Trying to use a self regulating alt. in an external regulator altrenator circuit can cause all sorts of problems.

HOPE THIS MAKES THE MUD CLEARER
 

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I had the same issue with my 1971. What I ended up doing was to find the output wire from the internal regulator, and "looped" in to the post on the back of the alternator. As soon as I did that I now have 13.8 - 14.2 volts to the battery, and things are running fine. What the above poster said about running an internally regulated alternator on an externally regulated wired car is spot on. Hope this helped. I can take a pic if needed to show what was done, I am at work now. Tomorrow morning would be the earliest.

Tiny
 

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I had the same issue with my 1971. What I ended up doing was to find the output wire from the internal regulator, and "looped" in to the post on the back of the alternator. As soon as I did that I now have 13.8 - 14.2 volts to the battery, and things are running fine. What the above poster said about running an internally regulated alternator on an externally regulated wired car is spot on. Hope this helped. I can take a pic if needed to show what was done, I am at work now. Tomorrow morning would be the earliest.

Tiny
ya id like a pic please. to see how it looks compared to my 72
 

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Discussion Starter · #18 ·
So I returned the alternator and got a new one and had it tested at AutoZone before the exchange and the new one tested fine. Came home and installed it (revved it up to excite it) but still 10.5-11.5 volts

I had the same issue with my 1971. What I ended up doing was to find the output wire from the internal regulator, and "looped" in to the post on the back of the alternator. As soon as I did that I now have 13.8 - 14.2 volts to the battery, and things are running fine. What the above poster said about running an internally regulated alternator on an externally regulated wired car is spot on. Hope this helped. I can take a pic if needed to show what was done, I am at work now. Tomorrow morning would be the earliest.

Tiny
If you mean you looped the #2 terminal on the alternator to the battery post on the alternator to "excite" it as soon as there is current then I tried that as well but still didnt help.

Hello. In 1969 Chevrolet used alternators with the external regulator. Around 1973 or so they started using alternators with the self contained regulator. The one wire system uses the self regulated alternator. Your NOVA is probably wired for the external regulator. A fairly simple wiring modification is all that is needed to run a self regulating alternator.

This may be your problem. Trying to use a self regulating alt. in an external regulator altrenator circuit can cause all sorts of problems.

HOPE THIS MAKES THE MUD CLEARER
This I am a little unclear on. The engine is not stock as it was originally a 6 cylinder car and was swapped out for a crate 350. The car had a one-wire self regulated alternator on it when I purchsed it but it also has not been charging since I purchased it.

So now I have to ask, where might the external regulator be located? And where could I get info on making the modification you were talking about?

Again thanks to everyone for their responses
 

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So I returned the alternator and got a new one and had it tested at AutoZone before the exchange and the new one tested fine. Came home and installed it (revved it up to excite it) but still 10.5-11.5 volts
Have you tried grounding your alternator case to the engine block?

You haven't mentioned how you're mounting your alternator, but it's possible that your alternator isn't getting a good ground. Is your alt bracket painted or otherwise isolated from the engine block ground?
 

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Discussion Starter · #20 ·
Have you tried grounding your alternator case to the engine block?

You haven't mentioned how you're mounting your alternator, but it's possible that your alternator isn't getting a good ground. Is your alt bracket painted or otherwise isolated from the engine block ground?
It should be grounded to the block via the mounting bracket shouldnt it? It is a chrome bracket.

Here are a couple of pics so you guys can see the setup I have currently



 
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