Ok... heres a good one: I've had my car for about three months - most of the time it's been in storage - never once lost a charge during the cold winter - even after sitting for weeks without starting. Last week, I brought it home from storage and started some detail cleaning on it - everything was fine.

Then, while driving it, it seemed the FI was messing up - just wasn't running that great. I get home, go to restart it and the battery is DEAD.

The PO put the wrong battery in it anyway, so I went and purchased a brand new battery today. I put it in, the car fires up and runs great - for a minute - then it seems like its acting up again. I shut it down, try to restart, and the BRAND NEW BATTERY IS DEAD.

Here's the kicker: My GEN light works - comes on during key up, but does not stay illuminated while running. How could a brand new battery get immediately drained after running for just a few minutes unless the ALT is bad - but then again, why am I getting no GEN light?

PLEASE HELP! Possible Voltage Reg problem?

yes. possible ...

you got a multimeter? get the thing to start and see how much voltage the alternator puts out ...
Andy

Even if it is putting out nothing at all it should not have killed that battery so fast

unless there is a large draw that you don't know about. I agree with Andy, break

out you VO meter and check voltage, amp draw and check the continuity of your

ground straps. Better yet clean your G straps and + batt cable, fresh start.

If the alternator had reversed it's polarity (internal short) would it actually DRAW amperage?

Just spoke to my dad (life-long electrician) and he suggests a possible internal short to ground. I'm interested in this outcome

that would drain it in a hurry ...

I know that a polarity shift would damage electronics, don't know if it would cause

a draw.

--><div class='quotetop'>QUOTE(scotty b @ May 4 2007, 06:45 PM) </div><div class='quotemain'><!--quotec-->
Just spoke to my dad (life-long electrician) and he suggests a possible internal short to ground. I'm interested in this outcome
[/quote]

Scotty - internal short to ground where? The ALT?

Would a bad ground cause problems too? I've never experienced this where a fresh battery gets totally juiced within a few minutes. I don't know what has changed, it was fine.

Maybe you just got a bad battery?

I would start with the simple stuff.

[quote name='customstarr' date='May 4 2007, 07:43 PM' post='896571']
--><div class='quotetop'>QUOTE(scotty b @ May 4 2007, 06:45 PM) </div><div class='quotemain'><!--quotec-->
Just spoke to my dad (life-long electrician) and he suggests a possible internal short to ground. I'm interested in this outcome
[/quote]

Scotty - internal short to ground where? The ALT?

Would a bad ground cause problems too? I've never experienced this where a fresh battery gets totally juiced within a few minutes. I don't know what has changed, it was fine.
[/quote]

A bad ground connection would not cause the rapid mbattery drain. What he was refering to is a short to ground within the alternator itself. That would drain the battery rapidly

[quote name='SirAndy' date='May 4 2007, 07:52 PM' post='896538']
--><div class='quotetop'>QUOTE(scotty b @ May 4 2007, 06:45 PM) </div><div class='quotemain'><!--quotec-->
he suggests a possible internal short to ground.[/quote]

that would drain it in a hurry ...
[/quote]

Should also get hot enough to smoke and cause a HUGE stink...

BJH

Sounds to me your blaming the battery / saying its dead as a consequence of the car not starting, seems to me you don't have any data to back that up.
There are a lot of things that will cause a car not to start as you put it.
In short the only thing on the car that can draw that type of amperage would be on fire so its not likely..
Check the voltage from the battery terminals not the cable connections.
My guess is theres something else going on.

Was the new battery charged when you installed it?

--DD

Break out your volt meter and do some measurements. Don't have one, buy one. A volt meter is essential for working on these cars.

By the sound of it, you have some other problem besides a dead battery. Could just be a bad connection somewhere. Give us some details and we'll nail this thing down.

Try some of these tests:

1) Visually inspect all ground straps for corrosion (green color is bad), breaks, or loose connections. Check ground strap on the transmission to the chassis. Check ground strap from battery to chassis. Your alternator may even have a ground strap. Have to look under the engine for this one.

2) Ignition off, measure battery voltage from battery terminal to battery terminal. Should be 12.6 or so.

3) Ignition off, turn on headlights or just parking lights if headlights don't come on with ignition off. Measure:

a. Voltage battery terminal to battery terminal. Should still be around 12V.

b. Measure voltage from each battery terminal to its clamp. This must be 0V else you have a dirty contact between terminal and clamp. If not 0V, remove clamp and thoroughly clean terminal and clamp. A minute layer of oxidation or corrosion will cause high resistance and no start.

c. Measure ground battery terminal to chassis. Again, must be very close to zero.

A voltage drop of more than 0.1-0.2V across any connection should be considered suspect and disconnected and cleaned thoroughly. The metal should be nice and shiny on both sides (like cable and chassis or clamp and battery terminal).

4) Ignition on, car not started. First disconnect +12V to your coil to protect either points and coil or Pertronix or other electronic ignition. Repeat 3a, 3b, and 3c.

If you have a massive short to ground, the small wires on the positive battery terminal will start to heat up. The large wire on the positive terminal is for the starter and shouldn't be an issue if the starter still works.

5) Ignition on, car running. Repeat 3a, 3b, and 3c. For 3a, you should see about 13-15V on the battery terminals.

6) If the car won't start, measure battery voltage as the car is cranked. May require 2 people, one to crank, one to hold the voltmeter leads. Battery voltage should drop to 8-10V during cranking. Measure on battery terminals, not clamps. If battery voltage looks ok but no start, try measuring (during cranking) each battery terminal to its clamp. Should be near 0V. Also for ground, check battery terminal voltage to chassis ground. Again, should be less than 0.1V, 0.2V.

Good luck and happy troubleshooting,

Spoke

Top notch advise.

Two things - first, as DD said, you have to make sure the battery is fully charged before you install it. The only way to reliably do this is to either use a manual charger and measure the specific gravity of the water/acid, or to use an automatic charger.

Second - your fully charged battery should read 12.75 V with a DMM. Not 12 V, not 12.2 V, not even 12 V, it's got to read 12.75 V. If it reads less, then it's not fully charged. To measure this correctly, you must first remove the surface charge - do that by turning on the lights for 10 minutes before measuring across the battery posts with your DMM.

I think there may be some confusion here.

The old battery was drained the last time I drove the car - knowing it was the wrong battery anyway, I decided to buy new. Bought new battery (Duralast), charged to FULL with Auto-Charger, installed and started car. Car was run for approximately 5 minutes and then was turned off - immediate restart was tried but the new battery was completely drained. When the battery is recharged with charger, the car starts and runs fine, but the battery is drained again.

There is no drainage of the battery when the car has been sitting and not running. This drain only occurs with the car running. The GEN light comes on with key up, but goes off after start and never comes on during run.

I'm going to get some voltage readings and check my grounds and such ASAP. The battery cables/terminals were cleaned and correctly tightned upon install.

When you try and start immediately after running and the car won't start, what specifically does it do? Will the starter not turn at all, will the lights dim when cranking (or trying to crank) etc. Have you ever experienced the hot start issue these cars have, and are your ground straps at the battery and at the body all clean and tight, as well as the spot they are groiunded to?