Parasitic drain on battery- probable causes?

[Evans Ward]

My battery after full charge will discharge if car sits (not running). I know it's not the battery as I just purchased a new one. Could a faulty external voltage regulator be a posible culprit? I have the standard HD alternator (car has AC) with the external VR. I pulled the VR off and it wasn't a factory Delco-Remy one being much lighter without any markings other than a part number. I have a used VR (factory Delco-Remy) from a '70 350 Skylark car I scored from a junkyard- are they the same as on the 455 cars? Car has no memory settings or killer aftermarket radio- only stock AM /FM one. Something is draining battery. Just wanted some ideas before I start troubleshooting a possible bad ground? I did take some voltage readings with the two VR's with car sitting with terminals attached at batt, running at idle, and at 2000-2500 RPMs. I can post them if that will help diagnose my problem.

[hotrod_06010]

I don't know about your car, but on mine to light in the glove box was staying on doing the same thing- draining the battery down, Just a thought make sure all your lights are off including brake lighst(sometimes switch sticks). Just one suggestion.

[David Gramlow]

Along Dan's line of thinking, last summer I found that my interior lights were no longer turning off when I closed the doors, figure I have a bad door jamb switch I need to replace, so I've temporarily pulled the fuse out. It was hard to notice, since I don't typically drive the car at night. Sorry I don't have any advice on the VR's.

[txgwildcat]

Check and see if all your interior lights are working correctly.

[Adam Whitman]

if you have an old analog voltmeter do the following. unhook the positive terminal and put it in line between the battery and the cable. It should register a voltage if you have a voltage draw. Unplug your alternator and see of the voltmeter registers different. then go to the fuse block and start pulling fuses, checking the voltmeter after each one. When you get to the right circuit, the voltmeter will go to zero after pulling that fuse. Now you can hunt down where the touble is.

good luck!

[Evans Ward]

Thanks for the responses fellows!

I do know that all the interior lights work and turn off as they should. Only one I have a question about would be the trunk light so maybe I need to get in there and have my wife shut it (unlock it too! :pp ) and check to see if trunk light is going off. I will need to check that glove box light too.

Adam- could I do the procedure as you described with a digital voltmeter? I don't have an analog one.

[CyberBuick]

The glove box and trunk both have ways to check without fully closing them. Thereshould be a button in the glove box that works the light. The trunk light goes on and off as the lid is opened and closed. At night, open the lid then kneel down as you close the lid, once you get down to about 6inches left before closed, the light should be off.

Do what Adam suggests with the meter and see. I'd bet when you unplug the alternator the drain goes away.

[yuk]

go to the fuse box and do the voltmeter test on each circuit one at a time. all you need to do is pull a fuse and test the 2 terminals that the fuse came from ..... if no votage is passing through, put the fuse back and test the next one .... eventually you will track down the circuit/circuits that were probably draining your battery.

[Adam Whitman]

Because most digital voltmeters have virtually infinite resistance, I don't think it will work. You can try and test to see, but I have been told that say a Fluke meter won't do it. You might be able to use the amp mode, but chances are that your draw will exceed the amp rating of the meter, unless it goes to 10 A or so.

[Evans Ward]

Car battery was dead last night so I still have a short and/or parasitic drain that is discharging the battery. I couldn't find my glove box light- it may be behind liner and will look when I can. Was it mounted at top of box? Did see the switch that the box trips to shut it off. I got in car, shut doors, and pushed that switch but nothing happens- no light or anything. Can someone also tell me about the ashtry light? Mine isn't working but I found that small cylindrical like aluminum pice attached to wiring- is that the bulb and where does it mount? At this point, I need to break down and purchase an analog voltmeter and will check out Harbor Freight's selection. What features on this unit do I need to do the in-line testing as Adam described? Haven't had a chance to review fuses at this point but will do so. Keep any feedback coming that will help aid in this situation. I really want to get this car back on the road- seems like as quick as I fix one problem, another develops! :Dou:

[D BERRY]

This may sound weird but when I got my Skylark it had the same problem and a local mechanic told me to unplug the wire on the cigarette lighter, problem solved. You should be able to get a analog volt/ohm meter at Radio Shack for $10.

Dave Berry

[CyberBuick]

The glove box light should be right behind the button. On the left side panel towards the top. The ashtray light is attached to the wire itself, take some pliers and pull the cover off the base as it's a two piece assembly. When the covers removed, you'll get the bulb. hth

[yuk]

yea my sister used to throw change in her ashtray ..... her lighter recepticle was nearby with no lighter in it ..... one of her pennies went into the lighter hole and she didnt know it and her battery began doing what you describe ... it would drain over night .... sometimes not ....... then one day she hit a bump in the road and the digital clock messed up on her radio, interior lights stopped working, and power locks quit too!!(chevy lumina). everytime she touched a new fuse into the block it would blow ... after my brother in law had scratched all the hair off his head tryin to figure out what went wrong, my nephew was lookin around in the car and happened to notice the penny in th lighter hole ....PROBLEM ELIMINATED.
CLOCK SUSPECT:
does your car have an anlog clock that no longer works? sometimes the "points" inside them stick on (usually from an old rotted capacitor) and drain batteries. if your clock dont work but the plug sparks when you plug it in or unplug it, it very well could be the problem.

BATTERY TEST:
just to be on the "for sure' side. unhook your (charged) battery and let th car set for a day or two. hook it back up and then see if it ends up being drained. your new battery might have a problem ... it wouldnt be the first time.

keep us posted!

[Evans Ward]

Yuk: no factory clock in this car as it was removed and replaced years ago with one of Y1's factory appearing in-dash tachs. It is definitely not the battery as I had done what you described with a full charge outside of car- battery will keep it's charge for days when not hooked to terminals on car. Recently bought a new Champion battery too and it killed that one after two days in the car sitting and hooked up.

I know now where NOT to look for an analog voltmeter- Harbor Freight! Only had one model and it was digital. I'll go by Radio Shack unless one of you have a better suggestion.

Cyberbuick: thanks for the tips on locating the glovebox light. Didn't get a chance to work or look at it yesterday.

Still going to try that tip on unhooking the lighter....

Keep the tips and help coming guys- I appreciate it!

[Evans Ward]

Re: the parasitic battery drain with car sitting- here's latest update: I took my new analog multimeter and put it in-line between positive battery post and positive post of battery. I measured voltage at 12.5v. Unplugged alternator- no drop in voltage. Pulled each fuse one-by-one and chacked for any voltage drop- none seen! Votage stayed consistent at 12.5v Checked glovebox light switch which was intact but no bulb there-consulted manual for bulb type, had one on hand, and light works fine. Also goes off as it should when glovbox door shuts. Lights in side compartment area in interior go off when jamb switch/ doors shut. Ashtray light appeared blown and will be replaced once I purchase another. Anyone know how that light attached to ashtray? Mine was dangling and I couldn't find how to attach in manual? My next step was to disconnect wire plug at cigarette lighter and see if that works to help with battery drain. If that doesn't cure drain, I plan to disconnect and take out fuse to radio to see if that matters. I can also take out alternator and have it chacked at a place like Advance or Auto Zone. Big thank you to my friend Russ Waters who called yesterday and gave assistance into this concern. One other quick question: with a quick disconnect battery switch- should it go on positive or negative post at battery? Anyone else have any ideas on my problem???

[CyberBuick]

The ashtray light just clips to the dashboard from underneath.. Take the ashtray out and look up at the edge of the dash there where you removed the tray. You should see a square/retagular shape cutout with flap type edges. Take the light and just clip it back in..

Did you try taking the multimeter to the fuses themselves? Putting on the battery I wouldn't think would show anything as your drain is probably a small one that take all night to do it's damange.

[Adam Whitman]

Did you disconnect the big wire on the back of the alternator too? If it has a bad diode that can do it. Also unplug the voltage regulator. Not to insult your intelligence, but is there an underhood light?

Keep plugging away, you'll find it. The ashtray light should only be on with the headlights/dashlights.

[custom sky]

I know this problem from experiance. I got rid of the external regulator and had the alt. rebuilt to an internally regulated 105 amp output. Since you didn't mention that you had done this I can only assume that the problem may be at your regulator like you origionally thought. If the wireing to it is still the origional I don't have any thing to add. If you have changed any of the wireing the regulator may be staying on draining only 1/2 of an amp per hour. This very likely won't show up on your meter. Try and disconnect the regulator and see if the battery drains over night. If not problem solved. The regulator is bad or the wires going to it or to the Alt. are crossed. Check to make sure the wires going to the Alt. are not loose and are connected properly. If the nut that holds the positive wire onto the Alt. is loose you could be shorting out. I don't know if any of this will help but it solved my problem and all I had to do was change the wires going into the Alt around and it was fixed. I usually took 2 or 3 days for the battery to go dead but I also have a gell cell that holds a charge for a longer period of time. Good Luck.

[GSMAG]

Try pulling all of the fuses, one at a time. The one that arcs as you reinstall it will show which ircuit has the drain on it. Obviously it'll have to be a little dark while you do this, but it works.

[2 68 Rivs]

A bad alternator diode will cause what you're experiencing. Just as an experiment, maybe you could try charging the battery and reconnecting it, then wait a while, maybe an hour or so, and then feel around on the alternator. If it's warm, you've may have a bad diode. Or disconnect the alternator and check ohms between the output terminal and ground, should be very high, 300K ohms or more.

[bignastyGS]

Here's another thing to look at. I had an 81 Regal that was a daily driver.The battery started to drain overnight like yours too. I pulled every fuse,unplugged all lights and the wire off the lighter but still had the same problem.After a few weeks I found the problem.The wire that is in the steering wheel(with a spring on it) for the horn was rubbed open.It was not enough for the horn to blow but enough to draw the battery down.I put all kinds of electrical components on the car and fixed it with a $.50 cent piece. This may not help but worth a look.
Pat

[GSThunder]

I'm gonna agree on the voltage regulator being suspect. Common for the contacts to stick. Have you felt the regulator after sitting a few hours? If it's warm to the touch it's probably sticking and conducting voltage.

[Evans Ward]

Checked the car this afternoon- battery voltage was 12.5v right where it was yesterday. That's good news as the battery was hooked up overnight on the car. One thing that was changed that I failed to mention was the quick disconnect battery post piece which I had on the negative post. I was trying to open it up to fit it on the positive post but broke it. I wonder if that had any bearing with this issue? I've also discovered that the ashtray light works when grounded but, yet for the life of me, can't find where that piece mounts too even with CyberBuick's instructions? :confused: Anyone have a digital camera when they can snap a pic of the light as it sits and mounts? Someone else asked if the car has an underhood light.... no, it doesn't. I'm not the most skilled individual with a multimeter so maybe one of you can tell me where to set it to measure current at fuses? Am I looking at DC amperage here and which probes go where? Key on and/or with anything else on? My meter has several settings for DC amperage and I'm not sure which one to use. Owners instructions don't address this either? Voltage regulator was changed out to an original unit and it doesn't feel warm to the touch. Neither does alternator. I did disconnect cig lighter. Well, we'll see tommorrow where that battery stands..... Thanks folks for all the help and keep it coming! :Comp:

[BillMah52]

Evans,
Did you check to see if there is a dead short somewhere?
If you have a test light, run one probe to neg. battery terminal and the other to ground anywhere on the engine. If you get a light you have a short.
Had a similar problem not too long ago. Turned out to be a bad ignition switch.
Spent many hours tracking that one.
Good luck!

[Evans Ward]

Battery is holding charge! One of the changes or combo of troubleshooting tricks seems to be working. I'm leaning towards it either being one of these three: change in external voltage regulators (although the one replaced could have been good?), unplugging cig lighter, or elimination of the quick disconnect battery switch off the negative terminal. I may reconnect the cig lighter to see what bearing it may have. Hey, and I even found the housing where the ashtray light goes too! Didn't know I needed to take out housing with 4 screws to access that panel. Many thanks to all who helped me in this electrical gremlin. Sure was nice to be able to drive the car away from home on Sat and have it crank later for return!:bglasses:

[yuk]

i am 100% positive it was not your negative disconnect.

to test your lighter socket. keep it unplugged and take you trusty volt meter
1.turn the meter on ohms
2.hook the one test lead to a good ground
3.take the other test lead and carefully touch it to the backside of the lighter socket where the orange lighter wire was once plugged in (usually its a little piece of bolt that the wire was once plugged into). if your meter show ANYTHING, any movement at all, you have a bad/dirty/crusty lighter socket.
if the meter does absolutely nothing, the socket is probably fine.

try these tests with and without the lighter resting in the hole.

[Evans Ward]

Thought I had whipped this problem but it has reared it's ugly head once again! I replaced external voltage reg with a Wells VR715 (solid sate unit). Battery is known good by Auto Zone test and by multimeter check. I actually have two batteries (one almost brand new) that I rotate in and out during this problem. Something is definitely killing the battery and it still appears to be a parasitic drain. I've chased every loose wire, changed all bulbs blown, and checked about everything I can think of. I will change the alternator out as I've recently purchased a rebuilt and restored original date coded unit. I'll give that a go and see what happens. Battery will go dead with car sitting for about 3-4 days. If the alt replacement doesn't cure it, it may be time to pay some $$ and put in the shop with the electrical gurus. I'm all ears if anyone wants to throw out some suggestions.

[Marco]

Evans Ward said:I'm all ears if anyone wants to throw out some suggestions.

Hi Evans -

Short term solution -

I have a battery cuttoff switch I installed on the ground. Every time the GS goes into the garage, I disconnect the switch.

Like I stated, short term solution (at least your car will start the next time).

[Evans Ward]

Marco,

I did have one of the quick disconnect switches on the negative cable at battery post but I broke it tightening it up. I probably should purchase another as my car can sometimes sit for days or weeks between drives. I really want to get this car back in a dependable and reliable state where I will have confidence in it. I have to say that my 87 Turbo Regal (daily driven) never misses a beat and has only let me down a couple of times. One day.......

[Evans Ward]

Got the new alternator installed yesterday. Hope you can't mess it up by clocking the back cover as I had to do this so the connectors would line up where they needed to go. Here's my question of the day.... I noticed when I took off the previous alternator that nothing was attached at rear at negative connector at rear of alternator? Is that standard? Should something be there? Only noticed the main two prong connector and a wire at positive conncetor at rear of unit. Someone please clarify for me. :confused: After buttoning it up, it seems to work well and voltage looked to be around 14v with engine running at around 2000 rpm sitting.

[462CID]

One of my endless problems with my Regal was a drain on the battery....had a worn off spot of insulation on my positive battery cable that was rubbing the frame.

[Evans Ward]

Chris- that's another area I haven't checked yet but will. Thanks! Problem is still there. With cables attached to battery, she loses approx 1v daily. Two days sitting still with cables on and she won't crank. I got tired of charging batteries and shifting them out so it sits with the neg off the battery. Haven't had time to check anything or even call the shop to see when the electrical gurus might could look at it. Been too busy as well as it's been way too hot and humid here!

[Evans Ward]

Which chapter is this in this never ending saga??:Dou:

Problem still exists. Was planning to drive car to repair shop today but car wouldn't engage starter! Wouldn't do anything when trying to jump start it either. Finally gave up and called towing company to take the car to the shop. I have the feature on my auto insurance policy of reimbursement for towing. The tow driver complimented my car and said that he had been at this job for a month. Stated his girlfriend had been after him to take his picture in the tow truck. He said that opportunity was now at hand with my GS in tow on the ramp truck as he planning to swing by his girlfriend's place for the photo opportunity.

I will post back on the report from the shop on this electrical problem after a hopeful resolution.

Does it ever end?? :Do No:

[flynbuick]

Evans :

I suggest you buy a clamp on amp meter from Harbour Freight which does not require you to interupt any circuit to see where current is being drawn. A reading close to the battery compared the circuits close to the fuse block should quickly isolate the branch where the problem is located. Then examine the schematic to see what is on that circuit that could be the problem. Much easier on the nerves than guessing here and there.

[Evans Ward]

Jim,

I wished we lived closer and I would pay you to fix these electrical problems. I'm still learning and have along way to go to develope some competencies mechanically. My wife is an Electrical Engineer and I can't even get her to help me out with the GS! She's understanding but working on them isn't her cup of tea. Electrical issues really throw me for a loop. I know I have throw some money at the car in this area and have gone with some guesswork too. I just want to get this thing fixed and be able to enjoy this car and have it be reliable and not let me down.

Aren't you up in the Charlotte NC area? I was up that way back late May for a National conference that was job related. I was at the Westin and got to go to Speed Street as I was there during the week prior to the Coca-Cola 600. Great time!

[flynbuick]

I am 180 miles east of Charlotte near Raleigh.

Call your local GA airport and find the closest avionics shop. They will have a tech used to running down tougher gremlins on aircraft that can help you. In the military they are called sparkchasers.

[tlivingd]

hmm idea...

have you pulled every fuse one at a time and checked for an amp draw across them? you can then atleast identify the circut causing the problem.

my honda had about 4 milliamps and would be dead in 7 days. (its also the same size battery as our SB skylarks

the digital clock/radio constant power would pull about 1 milli.

I found out my alarm I added had a bad relay and the relay would short and leave the parking lights on with a very faint glow.

nate

[Evans Ward]

I am totaly relieved that this long playing saga with this electrical problem is now over as the shop found the problem. I've had the car back a couple of weeks and the battery is reading 12+ volts sitting which makes me happy! I've been reluctant to post as to what the shop found as to the culprit. I'll tell ya'll but want ya'll to go easy on me- OK?? Here goes- shop called a couple of days after they got the car and said they had found the drain on the electrical system- they said "it's that toggle switch you have underdash and when in the ON position it is pulling voltage". They went on to say that no drains were evident on the car with this toggle switch in the OFF position. They then asked, "what's that toggle switch for anyway?" It's my toggle for the switch pitch tranny and I overlooked the obvious and evident as the car sometimes would sit with the switch in the ON position. Now I know and understand that the SP solenoid energizes when toggle is placed in the on position and pulls voltage, but I totally overlooked it! My moral to the story is for future reference not to overlook the obvious and easy things in troubleshooting. If some of you want to take away my keys or tools for a few days I'll understand! :spank: I'm really glad to have the car back and have this electrical problem resolved. :TU: Thanks to all who offered assistance and support. It was and is appreciated.

[Marco]

Don't beat yourself up Evans!

It's always the little things, and thankfully, it was something minor.

[BillMah52]

Another one of lifes lessons.
:jd:
Never overlook the obvious.
Like the faulty trunklight switch - Whodda thunk it!
Glad the ordeal is over for you.

[RED GS 1]

All in all it was still a very informative thread on battery drainage,everybody chipped in with different offerings on what could've been the culpret. A very interesting re-fresher course to anybody following along. I'm glad you got the problem solved,I'm sure we all learned a few things we had forgotten over the years,I know I did:Smarty:

[yuk]

what i dont understand is why that switch is not hooked to the "ign" terminal on the fuse block instead of having 12volts to it all the time .... that way when you turn the key off ... the switch would lose power..... or are you needing a way to do some "switch pitchin'" with th car shut off?.....:laugh:


now ..... tell us ......how much was th repair bill? :spank:

[Evans Ward]

Repair bill was about $100.00 but that included replacement of the wiper motor (supplied) as well as the car needing a new ignition switch. (shorted out) Some of that bill was labor to meter the electrical drain. I was pretty pleased with the repair bill. The shop I use sometimes will only work on domestics and are seasoned mechanics. They really enjoy working on old muscle cars. Shop manager was very impressed driving my 87 Turbo Regal one time saying he couldn't believe how strong that car runs. It is pretty modified for a street driver with bigger inj, bigger turbo, alky injection, etc. He's an old dirt track racer and he knows that car is a mid 12 second car. Says he's gonna start charging admission when the 70 GS is there due to all the floor traffic and people asking about it. Apparently, an older woman really wanted to buy the car on it's last trip!

You're right Yuk.... that switch should be wired to ignition with the SP but isn't. I'll leave as is and REMEMBER to keep toggle in OFF position when car is sitting.