Chevy Nova Forum banner

1 - 20 of 30 Posts

·
Registered
Joined
·
108 Posts
Discussion Starter #1
Ok, just got my '70 Nova back 8 days ago after having a new SP383 crate motor put in, new alternator, new battery, etc... Over a period of 6 days I drove approx. 250 miles & my ammeter was at 13+ amps. But all daytime driving. Then night before last I drove at night & the amps were only at 11 amps while driving the 30 miles home. Now even in the daytime It's only at 11 amps. I checked the battery with my volt gauge & battery is at 11.96 amps when it's not running. 11.85 Amps when I start it & 11.70 amps when I turn the lights on low. 11.69 on high beam. The car was re-wired for the 1 wire alternator, used to have a regular one. It looks they used 8 or 10 gauge wire & it runs app 4 feet to the battery. I read where sometimes you have run a ground wire off of the alternator. It doesn't have one... Any ideas? What can I do to trouble shoot it? Thank You! Bill
 

·
Registered
Mike - 74 Nova Baltimore, MD
Joined
·
1,495 Posts
Over a period of 6 days I drove approx. 250 miles & my ammeter was at 13+ amps....the amps were only at 11 amps while driving the 30 miles home. Now even in the daytime It's only at 11 amps. I checked the battery with my volt gauge & battery is at 11.96 amps when it's not running. 11.85 Amps when I start it & 11.70 amps when I turn the lights on low. 11.69 on high beam.
When you say "amps"... do you really mean "volts"?

If you turn your ignition key to the "run" position... but do not start the car (engine not running), do you see a ALTER (alternator) warning indicator bulb light up on your dash?
The alternator warning light in the dash acts as an "exciter" so that the alternator will begin to charge. If you do not see this warning light come on when you first start your car... or ignition key is in the run position with the engine not running, I believe that the alternator will not begin to charge.
Non-charging issue could be caused by a burned out alternator warning indicator bulb... or the new alternator not wired correctly.
 

·
Premium Member
1968 Chevy II Nova, Central Arkansas
Joined
·
2,003 Posts
Almost all of my non charging issues I have ever had to deal with when I have a known good alternator have been ground issues. Chrome and powder coated parts do not ground well.
 

·
Moderator
Joined
·
6,502 Posts
Ok, just got my '70 Nova back 8 days ago after having a new SP383 crate motor put in, new alternator, new battery, etc... Any ideas? What can I do to trouble shoot it? Thank You! Bill
Unless it you knew it had a taillight warranty or up to a 7 day warranty, I would take it back to the person that put the things in and see what they say.

If you start doing things and then cannot figure it out and then take it back to whomever did the work, they may say too bad, you messed with it now there is no warranty.

Jim
 

·
Registered
Joined
·
37 Posts
One wire alternators can be tricky. There are good ones, and bad ones. Bad ones don't charge well at idle. With the key off (or on, but not running) you should have around 12-volts at your battery terminals. Once the car is running the alternator will output about 14 volts if charging. You can read this value right at the battery. If you have been running around, especially at night, and the battery is not going dead, you might be ok. Google "one wire GM alternator" for more information.
 

·
Registered
Joined
·
108 Posts
Discussion Starter #6
Thank You Rif Raf, BLYOTH, Custom Jim, Stevejatc! Rif Raf, whoops make that Volts not Amp's! I'm old, the memories going... I don't have a warning light cuz it's a 1 wire alternator. I didn't really want a 1 wire but sort a got talked into it. My main concern is can you get a replacement if you break down in a small town in the middle of nowhere? I've got a brand new alternator that's not a 1 wire maybe I should have him put that on?... BLYOTH, Yes, my front pulley set-up is powder coated, so maybe a ground... Custom Jim, good advice I'll head over there this afternoon. I know the guys on a personal basis so it shouldn't be a problem. But if I mess with it it wouldn't be the first time I've made something worse... Stevejatc, last night when I got home I charged the battery for 90 minutes at 2 amp's. I'll post 4 pic's. 1st one is the reading at the battery, car not running... 2nd one a pic of the volt gauge when car is off... 3rd pic is the volt gauge when car is running... 4th pic reading at the battery with car running... Bill
 

Attachments

·
Registered
Joined
·
108 Posts
Discussion Starter #7
Why is the reading at the volt gauge the same when running as when off? Just checked again & the reading when running is like a 1/64" less when running. And reading doesn't change when I give it gas....
 

·
Premium Member
1968 Chevy II Nova, Central Arkansas
Joined
·
2,003 Posts
The readings you are getting are almost exactly what I was getting after I powder coated my brackets. I ran a ground wire from my alternator over to the motor and have not had any issues since. I already had a ground wire running from my motor to the frame of my car.
 

·
Registered
Joined
·
108 Posts
Discussion Starter #9
The readings you are getting are almost exactly what I was getting after I powder coated my brackets. I ran a ground wire from my alternator over to the motor and have not had any issues since. I already had a ground wire running from my motor to the frame of my car.
Thank You BLYOTH! Is this bolt for a ground? I'll just wire it to the engine...
 

Attachments

·
Registered
Mike - 74 Nova Baltimore, MD
Joined
·
1,495 Posts
My bad on the alternator indicator light (warning light) suggestion.
I just read up on 1 wire alternators and see that the indicator light is not needed (I'm old too... and still learning stuff).

I did read that when running a ground wire to your alternator to the engine block, be sure to use the same size gauge for the ground that is equivalent to the positive wire connected to the alternator. You should also run another ground wire (of the same gauge) from the engine block to the chassis/body.
 

·
Premium Member
1968 Chevy II Nova, Central Arkansas
Joined
·
2,003 Posts
Thank You BLYOTH! Is this bolt for a ground? I'll just wire it to the engine...
That's exactly where I bolted my ground wire.

I did read that when running a ground wire to your alternator to the engine block, be sure to use the same size gauge for the ground that is equivalent to the positive wire connected to the alternator.
I used one of those flat about 1/2" wide braded ground straps that I picked up at NAPA to go from alternator to motor. The motor to frame I just used a battery cable that had an eye on both ends.
 

·
Super Moderator
Joined
·
12,005 Posts
Mike a large wire is not needed for the ground, it is for the electronics inside to work properly. I used a 12ga wire from the case to the block ground from the battery.
I run a 140 amp 1 wire tough stuff alternator. It comes with a ground lug on it.
 

Attachments

·
Registered
Joined
·
108 Posts
Discussion Starter #13
Thank You Guys! Ok, it looks like the guy used 8 gauge wire for the hot wire to my battery. All I had laying around was 10 ga. so I grounded it with that but still doesn't charge. I'll head over to the auto parts store & get 8 ga plus a ground strap for engine to frame. But, how do I check the alternator? Bill
 

·
Registered
Joined
·
37 Posts
If you get the rpm above 2500 does the value on the gauge go up to 13-14 volts? Some single wire alternators don't sense dis-charge very well through the single wire, and take engine speed to "excite" and kick on. If grounding doesn't help, I would go back to a regular alternator with a built in regulator. Just my $.02. When I was deciding on using a single wire alternator on a hot rod I had, the research I did scared me away from them. But they have improved. Hope you get it figured out. Electrical problems can be frustrating! I am a Journeyman Commercial/Industrial Union Electrician. I would rather troubleshoot any building problem over automotive!
 

·
Moderator
Joined
·
6,502 Posts
Thank You

My main concern is can you get a replacement if you break down in a small town in the middle of nowhere? I've got a brand new alternator that's not a 1 wire maybe I should have him put that on?

Custom Jim, good advice I'll head over there this afternoon. I know the guys on a personal basis so it shouldn't be a problem. But if I mess with it it wouldn't be the first time I've made something worse... Bill
I drive my cars out of town now and then and to me a specialty alternator like a 1 wire would be harder to find than a standard one. Also if you get some good old boy helping you out he may have a standard alternator on something like a tractor that would work and be a bolt in/plug in setup.

I understand people wanting one wires but putting in a standard style is not that difficult.

I also like the fact that with the right parts you can get an adjustable regulator and not have to take what the alternator puts out which could be 13.1V or maybe 13.5V, but with an adjustable one you can compensate for voltage drops for systems with batteries in the trunks and be able to dial in 14.4V right across the battery terminals or even higher if one wanted (to a limit though).

With the pictures you have, I would make up or have this other guy that did the install make up a short ground wire to go from the unused bolt hole in the cylinder head right to the bolt on the back of the alternator. This would be very simple to do. With something like this you could get by with something like a 10 gauge wire but if you opt to go from the alternator case to the battery, then run probably a 4 gauge but this depends on the max amount the alternator can output. What another member said about the ground wire not needing to be large to me is wrong as the electrical system has to work in a loop to where if you have a 2 gauge power wire going to something, then you need a 2 gauge ground back to the source of power whether it is the battery or the alternator.

Maybe too on the spacer tube where it hits the back spot on the alternator, remove any powercoating there as well as maybe taking the 4 small front case to rear case bolts and doing them one at a time, put toothed lockwashers under the head of the bolts and then this might help tie the ground of the rear case of the alternator to the front case.

So you know if I have a fully charged battery sitting there with let's say 12.5V, then it is pretty much charged up and then once the car is started I like to see at LEAST 13.5V across the battery terminals up to about 15V and then I know the battery is getting charged and the alternator is working. If it's a volt or less than the battery nominal voltage then the battery will not be getting charged up.

Jim
 

·
Registered
Joined
·
108 Posts
Discussion Starter #16
Thank You Guys! Stevejatc & Custom Jim, ok, alternator to engine & engine to frame ground hooked up. 3,000+ RPM & volts don't go up... I put the alt to engine wire between the two bolt holes in the pic & the length isn't even 2"... I'll try putting the 4 washers on tomorrow... I went to the auto store I bought the battery at & they tried to test it. The tester said my battery was only operating at 35% & because of this they couldn't test the battery or the alternator. This didn't make sense cuz it should have been almost fully charged. So I disconnected the battery cables & charged the battery at 10 volts for 90 minutes. After charging the volt meter it read 12.34 volts. I'm leaving the battery disconnected for the night in case there's a short that's draining it. Tomorrow I'll go back to the auto store & have it checked. I'm thinking it's a battery due to the 35% reading. That just doesn't seem right. I can't imagine how it ran down that far that fast... Before I switch to a regular alternator I need to see what's going on. But I want to go to a regular one. I sort a got talked into it... Thanks again! Bill
 

·
Registered
Joined
·
108 Posts
Discussion Starter #17
Update! Battery is good. I think it's the alternator. I'm going to take it off & take it down to be tested off of the car to make sure. Just found out my battery has some kind of new technology. AMG Technology? So the battery charger I have at home won't charge it... New technology can kiss my ***! Oh, & my throttle linkage just fell off when I was on the freeway at rush hour Lol
 

Attachments

·
Registered
Joined
·
197 Posts
Incase you do not know, test to see if you have a parasitic draw.

Take a good test light and put in between the negative battery terminal and cable. (yes disconnect them and use the test light as a jumper). If the light is on, something is draining. Make sure everything is off prior. You can now disconnect items to find the culprit.

That's a bad picture, but the principle is right.
 

Attachments

·
Registered
Joined
·
197 Posts
An AGM battery is designed to be charged slow and low, and overcharging it can kill the battery itself. So, a normal battery charger can't be used to charge an absorbent glass mat battery.

I had a car storage facility that put a charger on my truck as a courtesy, even though it didn't need it. They killed my new red top battery.
 

·
Registered
Joined
·
108 Posts
Discussion Starter #20
Thank You LS Chevy II! I checked & no parasitic draw! I didn't know to check for that! Hmm, wish I hadn't of gotten that battery. I have a home & potable charger that won't charge with it... Thanks again! Bill
 
1 - 20 of 30 Posts
Top