Dead Battery--Again(Auugghh!)

Redcoupe864+3 · 10-27-05, 04:57 PM

This would be intriguing were it not already vein-poppingly frustrating. Just lost another fully charged new battery in the '86. The really annoying part is that the tech types just did a draw test on the system and found nothing out of the ordinary. The shop owner suggested that I start and run the car a little more often (At least every five days or so).

So it sat for five days, I go out and open the door--nothing. Abso-freakin'-lutely flat. When I got the car nearly two years ago, it'd sit for weeks in the middle of winter, and fired no problem. I've now put two fresh batteries in it, and both have had every last electron sucked out of 'em in no time. I have every confidence in my garage--been dealing with them for a dozen years-- but obviously can't keep unloading $60 or $70 just to get the Vette rolling. Thoughts/suggestions for 'em? Thanks!

Moonunit 451 · 10-27-05, 06:45 PM

Very colorful explanation

I'd drive it to them evry time you start it up or get a load tester to check it at home. Sounds like you've got an intermitant short.

The other thing you could do is leave it on a battery tender or some other type of slow low amp slow charger.

BTW, if you think this Vette is a mistake, I'd be happy to prove you wrong!

Redcoupe864+3 · 10-27-05, 07:09 PM

Thanks, Moonunit. Have begun to think it's maybe a short somewhere myself. Battery tender's a good idea; I'd just like to solve the actual problem first, then use the tender as insurance, if you will. Guess I'll just have the Vette flatbedded over to the shop, and tell 'em I don't want it back until it holds a charge the way it should.

Oh, and my apologies; any Vette (even a white one!) that runs low 12's gets nothing but endless "We're not worthy!" bows of respect from me and my bone-stock coupe. Thanks again.

Z06Marty · 10-27-05, 10:31 PM

I just came across the same problem on the neighbors honda. I fully charged the battery and started pulling the fuses from the fuse panel. With the key off and one fuse out, I was able to put my meter across the fuse leads in the fuse box until I found the circuit that was draining the battery. Hope this helps, Marty

Redcoupe864+3 · 10-27-05, 11:11 PM

Hey, nice idea there, Marty. I'll mention it when the Vette goes in. Has to be an abnormally high drain from somewhere, right? Thanks for the notion.

Moonunit 451 · 10-28-05, 12:59 AM

Thanks for your response on the white Al

Nice suggestion marty.

You got a lotta faith in your mechanic Al, and I understand that, but these kind of troubles can run up a big bill to find. I'm not lettin' anyone touch my old girl but me, as always.

You can find it yourself, but, if money's no object, more power to ya

wildbill486 · 10-28-05, 02:22 AM

Not neccissarily "high drain". My newly purchased service truck used to burn em up on about a two week program. Turns out there was a CB left on behind the seat that I forgot about. Turned it off...problem solved.

Doubt yours will be that easy.

scotch1 · 10-28-05, 07:10 AM

I agree with Wildbill.
Sounds like there is a small consistant drain. For example, something left on maybe faulty light or the visor light left on

Or a maplight or a glove compartment light that may have a defective switch or some other small light like a dome light. These items may not seem obvious and can escape detection.
Especialy since your charging system was checked, and there is not discernible drain.

scotch1

gmjunkie · 10-28-05, 07:21 AM

Quote:

Originally Posted by scotch1

I agree with Wildbill.
Sounds like there is a small consistant drain. For example, something left on maybe faulty light or the visor light left on

Or a maplight or a glove compartment light that may have a defective switch or some other small light like a dome light. These items may not seem obvious and can escape detection.
Especialy since your charging system was checked, and there is not discernible drain.

scotch1

Have Thay Checked the Alt for A/C voltage past Diode's!! A Shorted Diode(or Going Bad) will Do Just what your Talk'n about!! It will send a New Battery to it's Maker!! It will Suck the Life out and it won't Come Back!!

junk!!

Greg Gore · 10-28-05, 11:01 AM

I was surprised to learn keys left in the ignition, say when your car is parked in the garage causes the ECM to be energized and produces a significant enough draw to drain the battery after several days. Pulling the key out just enough to disengage the VATS chip or removing them will prevent this.

Regards, Greg

Redcoupe864+3 · 10-28-05, 04:27 PM

All youse guys--

Can't thank you enough for all the helpful suggestions. I'm sure the cause will be tracked down and addressed ( I do indeed have faith there, Moonunit; these guys really are top-notch diagnosticians. And frankly, I tend to "fix" things by getting a bigger hammer.) . And I'll be sure to pass your thoughts on to the tech types. 'Preciate it, folks.

Al

hdcwagsvette · 11-02-05, 08:07 PM

I had the same problem killing my battery every week. The best investment is a shop manual. Turns out the Oil Pressure Sender in the car was stuck in the closed position causing the fuel pump to remain on while the car was off. Not a problem anymore.

MBDiagMan · 11-04-05, 08:18 PM

It has to be either an alternator not charging or a drain. If the voltage in the instrument panel shows about 13.2 or more then the alternator is working.

If the alternator is working, put a DC Ammeter in series with one of the batter cables. If it is drawing more than about 100 milliamps then you do have excessive draw. With the ammeter still connected start pulling fuses one at a time. When you pull a fuse that drops the current draw that is the offending circuit.

Hope this helps,
Doc