Our 87 has always had a slow drain on the battery but over the last year it's gotten worse. It now completely drains the battery in less then a week.

How would I go about searching for a problem like this?

Thanks!

 

Ran a search on "battery drain" in the tech archives. This was only one of about 13 threads:
http://forums.corvetteforum.com/zerothread?id=564019

Should give you a place to start.

 

Good work Steel Blue ! :thumbs:

 

Thanks Steel Blue!

Looks like I have my work cut out for me today.

:seeya

 

First check at night for a vanity mirror light left on, and for an underhood light on. Do you have an aftermarket radio or audio amplifier or radar detector or theft alarm? Check them. Some CFers have found a seat adjust switch stuck on. Next, disconnect the neg cable from your battery and place an ammeter (VOM test meter) between the neg cable and the neg batt terminal. Wait for the courtesy lights to time out and then switch the ammeter to lower and lower full scale amps (towards 100 or 200 milliamps) and read the current. My 87 draws 27 ma. and GM says it should be less than 50 ma. Pull the 10 A courtesy fuse first so the lights stay off and don't pin your ammeter, then pull each fuse out one at a time and watch the ammeter. A fuse removal that causes a dramatic drop in leakage current is the circuit that will need investigating. If you have to, remove the nut on the jump start terminal behind the battery and one by one, remove the 8 red wires and watch the ammeter. There are also some circuit breakers and some unfused circuits that will need to be checked if you get this far without finding the circuit that is drawing excessive current.

 

During this past winter, I had found that my son left the vanity light on my '92 convertible. It drove me CRAZY until I found that!.

 

Is your battery charging OK? Meaning does the indicator actually tell you the battery's full when you're done charging it? If not, it may be that the battery went south from the de-sulfation process. This happened to me and it turned out to be the battery. Four batteries later and three self-installations I was back on the road. Turns out three of the batteries went to crap before they were even installed in the vette. If it tells you it's fully charged then you may have something left on in the car like the console light or glove compartment open.....something to that nature. If it isn't either of them, make sure you don't have any wires touching anything metal in the engine bay. If all these look OK, you may just have some bad battery cables. replace them and everything should be cool. Hopefully your alternator isn't shot yet and therefore causing the prob...before it does happen...I'd get it checked though. Check the alternator and the battery at an auto store or somethin before replacing the cables though. Keep us posted. :seeya


[Modified by MaSTeRofDZaSTeR, 2:42 AM 10/23/2003]

 

If you have the Bose radio, it may be your amplifier relay. Place your ear up to the speakers with the car turned off. If you hear any noise at all coming from the speakers then your amps are not being turned off by the relay.

This is what happened with mine anyway. FWIW. :)

 

:iagree:

 

jfb comes through time after time. :cheers: For me, I believe the underhood lights were the cause of my problem. :yesnod:

 

Damn, I forgot all about this thread!! :lol:

There were many problems. The battery cables were loose and not making good contact with the battery and the alternator was bad, probably killed it because of the loose cables. I replaced the battery and Alt and she's running great again. There's still a slow drain which I'll use the info gathered here to locate.

The underhood lights have been unplugged for years and I know it's not the vanity mirror lights although I hate those PIA's

Now if I can keep from breaking anything while running with Mr Mojo this weekend on Skyline Drive I'll be a happy camper!! :cheers:

Thanks again all! :seeya