OK so I have read a few posts about battery/alternator issues, but have not seen anything that has been able to help me with mine.

I have a 77 Corvette that was sitting for a while. I replaced the fluids, plugs/wires, Carb, intake, fuel pump, battery and alternator.

I can start the car when I have a full charge and it will run with no problem. I can stop, start whatever without issues. I drove it to work the other day (20 miles one way) and when I was about 3/4 of the way there it started to sputter and try to stall. If I put the car in neutral it was fine. Every so often when I pushed the gas pedal it would not want to go. When I got to work I left it running and saw no issues. I shut it off and the battery was almost completely dead.

I replaced the battery just before I left to go home and it seemed to be running and starting fine. Left for home and everything seemed to be OK. Got about half way home and the sputtering issue came back. I decided to put some gas in it just to be safe. Tried to start it afterward and the brand new battery was almost dead and the car wouldn't start.

Battery light comes on when key is on
Car stays on with negative side unhooked
Battery with full charge reads 13.5
At alternator with Key on 13.4
When running 14.6 at alternator
When running 14.4 at battery

One weird thing I do see is when my charger gets to a full charge the green light on the charger comes off then goes off and on again, until I turn it off.

 

If the alternator output reads 14+ volts when engine is running, then it "thinks" the battery is fully depleted and is trying to charge it up. And, just because a battery reads more than 12 volts does NOT mean that it has any capacity to start a car or keep it running for long.

I suspect that your battery is very tired and has lost almost all of its capacity. You can check this with engine OFF when you think the battery is charged up: just turn on your headlights (brights, too) and watch to see if the lights stay well lit for a minute or two. If they start to get dimmer quickly, you have your answer.

You could also have a problem with the 'exciter' circuit/wiring for the alternator (this senses the battery voltage and adjusts the regulator accordingly) or the regulator circuit which is inside the alternator.

 

A fully charged battery should run the car more than 20 miles without any problem. Either that battery is no good, or there is something wrong with the charging. Now for the sputtering problem, that could be unrelated, and the symptoms sound like a bad fuel filter or pump. Since that thing sat around for a long time long, I would take a look at them.

 

Sounds like you might have some EE background, nice little scenario,is this a test ?

 

I wish I was but this is for real!!

 

Thanks. I have replaced both of those recently as well.

 

Here is what I would try.
Start the car and unhook the battery, pos and neg and protect them from touching anything.
Now drive the car.
it should run fine running off the alternator only, then go from there.
If not then you have a dead short while the key is forword and you need to take it to a mechanic before it burns to the ground.