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Discussion Starter #1
I'm stumped over this one guys...for the past few months or so my battery seems to drain off if the car isn't started and run every 2-3 days. Once it's started it cranks right up after being shut down. It takes a charge okay when I've had to recharge it and passes load tests just fine. It's just when it sits for a few days without being started that I often find it getting weaker and weaker until it just won't crank the motor...lights work okay just not enough juice to spin the engine.

Now I'm on my second battery (hoping it was the battery itself) and it's doing it again.
I've checked to make sure that all components on the car are turned off and not running...I even removed the glove box light thinking that it might be stuck 'on' but to no avail.

Not sure if this helps, but I switched (one month ago - well after this problem started) to a new 'one wire' 63amp alternator, use an electric Comp140 fuel pump, fan, small 100 watt stereo amp, and an MSD 6AL ignition system.

Any ideas as to what is draining my battery even though everything in the car has been turned off? Electrical troubleshooting is my weakest link and looking for some help here...thanks in advance!

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1970 Malibu - Current 383 'Fog Fed' Stroker soon to be ZZ502 'fog fed' Big Fat Rat. Houston, Texas...Gold Member #39
http://www.chevelles.com/showroom/wescolby2.jpeg
Keep America Beautiful - Drive A Brute Force Chevelle!

[This message has been edited by Wes Colby (edited 03-17-2000).]
 

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It could have a diode that is open to current flow both ways inside the alt, might take it to a good electrics checker to see if they are bad. Most good auto parts stores can check the alt for many problems with it off the car.

Second, take a meter or light and check to see if the MSD small red wire is completely turned off when the key is off. I have seen some limited current flow, just enough to drain the battery, in this MSD actuator circuit. Lets the engine stop, then starts up again, like you left the key on.

Lots of other places, brake lights stay on, etc, but I figure you already looked at all the obvious stuff.

Anyway, just a couple of things to check.

I'd have put the 78 amp 12SI alt on it. Just me, though.
 

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If you have a current meter disconnect the positive battery cable, touch one lead of the meter to the battery post and the other to the cable to check for current drain. If you don't have a meter rig up a test light using a 194 dash light bulb. If you detect current drain it's just a matter of diconnecting things you suspect or removing fuses to find out what circuit is draining your battery.

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Steve Strasemeier (70SS 396, Fathom Blue/White Stripes)
 

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Discussion Starter #4
Thanks guys...here's what I've done so far with no luck. Checked for current through the small red wire off of the MSD box with the key turned off - no current detected IgnitionMan.

Next, I tested every fuse from the fuse block one at a time. Checked for current as you suggested Steve and sure enough there was current (using tester light with ignition key off) but after each fuse was disconnected, there unfortunately WAS current still being drawn from the battery...so it's definitely not any of the fuses.

Next, just for grins I disconnected the red 'charging wire' (sorry but I know little electrical lingo) that splices into the positive battery cable (at the battery terminal), and the current draw stopped when tested as Steve suggested. Tried tracing that red wire but it dissappears into a thick maze of factory bundled wires and ends up on the right front side just behind the headlights - from there I have zero idea where it goes.


One interesting note - I noticed that with that red wire disconnected at the battery terminal and the main positive battery cable reconnected, the car has zero juice...even the interior lights wouldn't come on...until I reconnected it back again...interesting.


Any more ideas guys?
 

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Wes,
The "large" positive cable supplies voltage to the starter only, for cranking. The small red wire you speak of supplies the rest of the car, including the ignition switch and all lights. It should make it's way over to the horn relay above the voltage regulator. I have a funny feeling that your alternator is causing the problem, though. With your test light in series with the small red wire, disconnect the wire from the alternator and see what happens. If a diode is bad, it will allow current to flow in the "wrong" direction. All the diodes should be in what we call the "reverse biased" condition when the car is not running..no current should be flowing through the diode pack. Check the alternator again.
 

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Discussion Starter #6
Thanks Jerry...still learning. I tried exactly what you said and with the alternator wire disconnected at the alternator, I'm still getting voltage thru the smaller red wire. However, when I reconnected the alternator wire to the back of the alternator the test light gets noticeably brighter. What does that mean? BTW, this is the second alternator with the same battery drain problem. Could it be that I've just got horrible luck in picking out alternators with diode problems? My next step is to take it to NAPA and have them bench test it.
Any other ideas?
 

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Wes,
Ok, so this may sound stupid, but have you checked the grommets behind the distribution block? That feeds the accessories.

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Better Late than Never Fred
Team Chevelle #400
If you're not the lead dog, the scenery never changes...
The '70
 

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Wes,
When you converted to the one wire alternator, how did you do it? Did you use a jumper to eliminate the external voltage regulator? Sounds like your problem is on the firewall side. Just for grins, pull every fuse out at one time and again check for current draw. Also, where did you tap power from for the amplifier and the fan? Make sure they're not hooked up to the "feed" side of the ignition switch circuit. Lotsa stuff to check!
 

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Discussion Starter #9
Riffers70, what should I check for? I know what you are describing but don't know what to check for or how.

Jerry, when I converted to the one wire alternator all I did was cut out the old 2-wire plug that my old alternator used to use and re-connected the larger single red wire (ie. one wire) to the back of the new one wire alternator. I also unplugged the old external voltage regulator to get rid of the 'alt' dash light that was constantly on since the switch to the new alternator. That's all I did and thought that that was all that needed to be done - did I miss something there?


I've already checked each of the fuses for voltage and with each one removed, there was always current hitting the tester light.
Darn light would never go out.

I honestly don't know which slots I used for the amp and the fan...if both items are not turned 'on' when the key is in the 'off' position, how could it drain the battery? Please explain...thanks for your patience.

[This message has been edited by Wes Colby (edited 03-17-2000).]
 

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Wes,
There's a jump that needs to be made when converting.
Check out the Tech Reference.
See if it matches up with what you have.
As for the distributor block, just make sure the insualtor is in good condition. Remove the one bolt holding it on and make sure the metal of the block isn't hitting anything behind it.


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Better Late than Never Fred
Team Chevelle #400
If you're not the lead dog, the scenery never changes...
The '70

[This message has been edited by Riffers70 (edited 03-17-2000).]
 

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Discussion Starter #11
Thanks Riffers, I checked out Wes's technical reference but from the way it looks, he's referring to converting your exhisting alternator to a 'one-wire' alternator. Mine is an actual 'one-wire' alternator straight from the box. I don't think that I needed to do anything to the old external voltage regulator because it isn't being used by the new alternator...just had to unplug it to get rid of the idiot light staying on.

I will check out the back of the fuse box like you suggested. Thanks again for your help!
 

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Hmmm...I changed mine over as well and I recalled jumping two wires. I'll check tomorrow and see what I see.

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Better Late than Never Fred
Team Chevelle #400
If you're not the lead dog, the scenery never changes...
The '70
 

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Wes, your alt has the jumpered regulator already, you don't need any other wire for charging. If you do want the idiot light to work, then find the light wire from the old regulator harness, and connect it to the number 1 terminal on the side of the alt. Light will work fine if the alt is in good shape. I've seen a few aftermarket one wires that had bad stuff in them.

It really does sound like either a ground problem or alt diode bridge gone away/regulator out. I do believe most of the aftermarket 1 wire alts come from off shore sources. I think the check will show something.

You can chance the internal regulator to a stock GM design, and make the jump from the outside, large batt terminal to terminal number 2 on the alt.
 

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Had a simeler problim once the contacks in the horn relay were so rusted they were joined together.Check to see if the relay is hot after the car sits for a couple of hours.Mine would almost burn my fingers off hope this helps.If so let us know.DDP 396.
 

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Discussion Starter #15
Thanks IgnitionMan...I will also try to find a bad ground. Snake, at this point I'm ready to try anything to find the culprit...where is the horn relay at? Thanks!
 

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I believe the horn buzzer relay is located just to the right(as sitting in car)of the master cyl. try diconnecting the wires one at a time to see if a circut is staying hot.I agree that this is most likely the culprit
 

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Oddball things that I have encountered that drain the battery:

clock (even if it doesn't work)
bad door switch that activates the dome light
bad ignition switch

I'd also look for things that a previous owner may have rewired (fusable links w/stranded wire) or wired around the fuse.

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OrrieG
64 Malibu HT Survivor
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The horn relay is beside the voltege regulater or under the washer bottle on the rad suport left side.
 

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Discussion Starter #19
Thanks snake but that isn't the problem either...I tested it and it still passes current thru the tester light with the horn relay disconnected. I'll keep looking...

OrrieG, in what way would a faulty ignition switch draw current from a battery. If the ignition switch is bad, how would you know? Being able to start her without a key?

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1970 Malibu - Current 383 'Fog Fed' Stroker soon to be ZZ502 'fog fed' Big Fat Rat. Houston, Texas...Gold Member #39
http://www.chevelles.com/showroom/wescolby2.jpeg
Keep America Beautiful - Drive A Brute Force Chevelle!

[This message has been edited by Wes Colby (edited 03-18-2000).]
 

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I have to ask. Is your amp turning off? Usually, you need to run the main power wire directly to the battery (or another unswitched power source) and another trigger wire to the power antenna or other switched source. If you have the trigger wire in the wrong place ir the amp's power supply is acting-up, it may not be shutting down.

Could it be something in the light switch, The headlights usually don't have a fuse so the switch would still be connected without the fuses.

What about the cigarette lighter. Same as above.

Can't think of anything else that hasn't been covered right now.

Peter
 
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