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12/12/12 11:54pm - Original Message: 'Good news and bad news'
daveo76
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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
Good news: I think my battery is OK.
Bad news: something else is wrong.  

I haven't driven or started it for about 3 weeks.  Batt has been disconnected with the quick release, but it was NOT on the trickle charger.  Last night out of curiosity I hit the key for a second or two before I hooked up the charger - plenty of cranking power.  In the past a few days of sitting with the batt connected and it will kill it.  So that tells me there's some parasitic drain going on - hmmm.  Any thoughts about where to start or what the most likely culprit is?  Factory alarm maybe?  


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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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12/13/12 12:25am - Reply: 'Re: Good news and bad news'
F4Gary Gold Member
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Grapevine, TX - USA

Vette(s):
1972 LT-1 convertible with factory air.

Joined: 8/26/2006
Posts: 870
I don't know Bo about electricity, but you could try testing for current at the fuse box with the ignition off.

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12/13/12 6:23am - Reply: 'Re: Good news and bad news'
crossfire1982
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Cramerton, NC - USA

Vette(s):
black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion

Joined: 8/22/2006
Posts: 1094

Im not an electrical guy either but some of the guys here are will probably chime in shortly.  Instead of giving my own advise, Im posting a link to a pretty good electrical troubleshooting post from another forum.  If I offend the forum gods by posting from another forum I apologize in advance.  Scroll down a bit to the post by ...ROGER...  Hope this will help you some.

http://forums.corvetteforum.com/c3-tech-performance/1783718-battery-dies-in-my-82-cant-locate-cause.html

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12/13/12 9:16am - Reply: 'Re: Good news and bad news'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19458
Parasitic draw on these old turds will definitely drain a battery after a few days....most of us have just come to accept it, and use the quick dis-connects on the batteries.
A couple of the most common drain problems are the clock, and the alternator. The alarm systems can also cause excessive drain, but there are usually other symptoms associated with that, such as an alarm that don't work, or blows the horn all the time. Un-plugging the relay will tell if it is an alarm issue.
Aftermarket stereos and other additions can also be a source of excessive drain.
These cars are old....with old wiring and stuff. Battery drain is part of the joy of owning them....LOL NOT!


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Joel Adams
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12/14/12 12:29am - Reply: 'Re: Good news and bad news'
daveo76
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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
Thanks, guys!  Good info.  Joel, you might be on to something with the clock.  When I was putting everything together this summer I fiddled around with my two mechanical clocks and got one of them working.  It even worked for a few weeks or so after I got it in.  But now it don't.  Possibly it's still causing a draw?  Chip, your link to the "other forum" was helpful, too.  (don't feel bad, I lurk there sometimes, but you do have to wade through a lot of infighting).  They mentioned the mechanical clocks on there, too.  I'll get out the test light and start playing around with stuff.  

In any case, a quartz clock conversion is high on the to-do list now for this winter/spring (even if it's not the source of my current problems)


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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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12/14/12 3:08am - Reply: 'Re: Good news and bad news'
crossfire1982
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Cramerton, NC - USA

Vette(s):
black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion

Joined: 8/22/2006
Posts: 1094
Dave, you are right about the "other forum", lots of good information there but also lots of egos and attitudes.  I lurk but rarely post there and consider C3VR my home, Im comfortable here.  Good luck with finding your current draw.

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12/14/12 7:35am - Reply: 'Re: Good news and bad news'
chances r Lifetime Member
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spicewood, TX - USA

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Sold them Both

Joined: 9/13/2009
Posts: 72
In my past experience, I have found that it can often be caused by a faulty starter.  A dead spot.  I am not saying that the starter will even show any signs of an issue even.  But it will draw your battery down.  The best way to know is to have it tested.  Which is a PITA.  You can disconnect the positive lead from the solenoid, and let it sit.  If it does not drain then you have ruled out the soleniod. And a short in the switch on the steering column.  Then disconnect the main battery cable and do the same. Sit for a couple of days and see if it drains. If it doesn't then the starter IS likely the issue.
 
Then check anything that may be direct wired to the battery. (ie. Stereo equipment, etc.)
 
It could be a dead cell in the battery as well.  Have had them show a full charge, but when you start cranking on it, that dead cell will show its ugly head.  I always look at a battery issue as the culprit if it is more than 3 years old.  Does not matter what the rating is.  After three years it is russian roulette.  If it is taking a charge everyday, by driving, or trickle charging, you won't notice it.  But a dead cell will drain the battery while it sits.  Whether it is connected to the system or not.  Have it checked.  They usually do not charge for it, and if you have quick connects, they can check it in the car with no issue at the local parts house.  Most of them anyway.
 
Hope this helps.
Mike


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12/14/12 3:34pm - Reply: 'Re: Good news and bad news'
kstyer Lifetime Member
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CUYAHOGA FALLS, OH - USA

Vette(s):
1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

Joined: 12/2/2003
Posts: 6410
Mine can sit for two months with everything connected and still start.  You don't have to live with it.
 
Get an inexpensive amp meter if you dont have one.   Many digital meters will read amps, some won't.
 
Disconnect the battery and connect the amp  meter in line between the battery and the cable you disconnected.  If you are over 0.3 amp, you have a problem.  The lower the better.   0.5 amp will kill the battery overnight.  Ideally it should be less than 0.1 amp.
 
A volt meter will NOT work for this.  I will avoid the explantion at this time.
 
Now watch the amp meter and start disconnecting fuses, one at a time.  If at any point the meter reading drops, you have found the circuit with the problem, and you can start disconnecting items on that circuit until you find the draw.  Be sure to have the interior lights turned off or they will show a draw that is not there when you shut the doors and walk away.
 
If all fuses are out and you still have the electrical draw,  disconnect the alternator, and then the starter.  By this time you will have found the problem.   It may take you a few minutes, or a few hours, but you will know for sure, and you can correct the cause.
 
Happy hunting.


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12/14/12 10:55pm - Reply: 'Re: Good news and bad news'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19458
NO disrespect to anyone, but....I'm not getting this one...
Disconnecting the cable from the starter will effectively kill ALL power to the car, so...there would be no drain at all...kinda like disconnecting the cable from the battery. Unless I'm missing something from the Zenmaster's, or the previous posts. Unless you keep the pink feed wires connected to the disconnected main starter cable, that is....
Did I miss something, or is my pea brain really that damaged from the '70s....Wacko LOL LOL

Using an amp meter and pulling fuses will certainly find the cause of excessive drain....but I'm just too dang lazy...and not flexible enough to hang upside down under the dash pullin fuses....LOLLOLLOL

Good to see ya on the forums again, Ken! Hug


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Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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4/12/13 12:53am - Reply: 'Re: Good news and bad news'
daveo76
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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
So I finally started doing some diagnosis on this problem.  It looks like it's the courtesy light circuit.  With an ammeter inline on one of the batt cables I pull about .33 amps with the doors and hood closed and all (that I know of) courtesy lights off.  If I pull that fuse, I show no current draw at all with the same conditions.  Any thoughts how that particular circuit would draw current with all the lights off?  Is there something else on that circuit?

Oh, and the clock has not been plugged in for any of these tests.  I was going to put my center cluster back together tonight but decided I better do this diagnosis first while I have access to the back of that panel.  

Thanks guys!


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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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4/12/13 11:44am - Reply: 'Re: Good news and bad news'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19458
Make sure the light in the storage compartment is OFF....those things can stay on sometimes.
Other things in that circuit? Heck yeah....ciggy lighter, and the light for the clock are both on that same fuse/circuit. Ermm


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Joel Adams
C3VR Lifetime Member #56    
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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4/12/13 12:36pm - Reply: 'Re: Good news and bad news'
rraider1
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Woodland, WA - USA

Vette(s):
1977 T-Top,350,Auto Black Ruby Pearl,Steeroids R&P conversion

Joined: 10/14/2003
Posts: 1152
courtesy light timer could be the culpret

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Bob R
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4/12/13 3:52pm - Reply: 'Re: Good news and bad news'
daveo76
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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
Thanks Joel and Bob. I'll check the thins you mention - specially cig lighter and compartment light. Bob, I don't think mine has a timer - lights go off as soon as doors are closed. Two other questions: could it be the "door ajar" light? Or the "key in" buzzer? Both have had some issues lately.

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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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4/12/13 9:41pm - Reply: 'Re: Good news and bad news'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19458
Yep...the ZX2 "Convenience" option, which included the dome light delay, dint go into the cars until '77. Thumbs Up

The "Key in" buzzer could certainly cause a problem, but you should be able to hear it...and it is kinda in the same circuit as the courtesy lights, since it uses the same door pin-switch to provide the ground for the buzzer. However, the buzzer gets it's power from the brake light circuit....which is on a different fuse.
The "Door Ajar" light should also be tied into the door pin switch circuit somehow, but it aint showin on the wiring diagram, for some reason....Wacko


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Joel Adams
C3VR Lifetime Member #56    
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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4/14/13 11:55am - Reply: 'Re: Good news and bad news'
daveo76
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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
Thanks, Joel.  I've narrowed this down now in that I know it's not the clock or the lighter as both are unplugged and I still draw .33 amps.  I'm guessing I've got some damaged orange wire somewhere in the courtesy light circuit that's allowing that amount of current to go to ground.  Or if the key-in buzzer or door ajar lights are somehow drawing the current maybe that could be it. More diagnosis - yippee.  

As an aside, I think the "clock light" part of that wiring diagram is a misprint.  I think it should be clock/lighter.  If the light for the clock was on that circuit it would be on all the time.  The clock light is on the same circuit as all the other gauge lights - gray wires.  The clock itself and the lighter are both on always-hot orange wires, which makes sense.  


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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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4/16/13 12:56am - Reply: 'Re: Good news and bad news'
daveo76
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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 831
Sorry for the many posts on this topic, but I think I'm getting closer.  Underneath the steering column there is a connector for the harness that leads to the back of the car - tail lights, cargo area light, fuel gauge tank unit, etc.  Unplugging this connector makes the current drain go away. It also turns off the cargo area light and the storage compartment light but leaves the front courtesy lights on.  Since I previously identified that removing the courtesy light fuse also eliminates the current drain I think I pretty much now know that the drain is either in the wiring between that connector and the lights or there is a problem with one of the lights themselves.  Sound reasonable?  Now to locate that fault exactly and fix it... 

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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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4/16/13 6:30am - Reply: 'Re: Good news and bad news'
Bobbi's78 Lifetime Member
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Coatesville, PA - USA

Vette(s):
1978 Silver Anniversary Paint w/Mahogany Interior

Joined: 3/17/2007
Posts: 349
Dave-
Thanks for doing the leg work on this - I too have a vicious drain & must disconnect overnite.  We tried checking some of the more obvious items, but never went through the entire fuse box...(unlike Joel, I AM flexible enough to get under the dash Wink LOL  but have not taken the time to do a full diagnostic).  I'm curious to see where your search leads you.  Keep us posted!


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4/16/13 11:25am - Reply: 'Re: Good news and bad news'
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19458
Bobbi's78 said:...(unlike Joel, I AM flexible enough to get under the dash Wink LOL

And I have the pics to prove it.....Evil Smile  LOL
It's good that you have narrowed it down to the rear harness. My money is on the storage compartment light....try removing that bulb and see how that works on the drain. If it doesn't change, then you may very well have a small chaffed wire somewhere in that harness, quite possibly where it runs under the trim plate next to the seat.


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Joel Adams
C3VR Lifetime Member #56    
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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4/16/13 8:47pm - Reply: 'Re: Good news and bad news'
Bobbi's78 Lifetime Member
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Coatesville, PA - USA

Vette(s):
1978 Silver Anniversary Paint w/Mahogany Interior

Joined: 3/17/2007
Posts: 349

Touche' Joel Clap

Dave-  I forgot to mention that originally the car couldn't even sit for a couple of hours without draining the battery.  We tracked it down to a dealer installed LoJack which was tied into the glove box light & was hot all the time (the actual unit was up under the dash taped to the ductwork below the speaker).  Needless to say we ripped THAT out. 


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4/16/13 9:33pm - Reply: 'Re: Good news and bad news'
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19458
Bobbi's78 said:  Touche' Joel Clap


ShockedShocked Wha'd you call me??! Angry

LOL Jest for that.....


Tongue
I hate diggin for parasitic drains...such a pain...disconnecting components one at a time, especially if you have to have the door closed, considering where the dang fuse box is on these cars....Angry




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Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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