Help! Slow Battery Discharge

-

blewbyoutobad

FABO Gold Member
FABO Gold Member
Joined
May 23, 2010
Messages
1,417
Reaction score
463
Location
Missouri City, TX
My 65 Valiant has a slow battery discharge. Usually goes dead in 2 weeks. I have put up with it for 6 years and finally I'm ready to fix it. I need more frustration in my life like I need a tax hike. There is an aftermarket MSD 6AL and a MSD retard box. I'm not sure where to start. Removed the battery disconnect at the neg terminal a year ago because the thing doesn't always work. Is there any simple way to trace the slow draw to the guilty device.
Thanks A-Body Members:banghead:
 
I'm having a similar issue on a93 Dakota, dead stock with no add-ons. Will keep an eye on this thread for possible help.

sent from my iPhone
 
EASY. Get yourself a 12V test lamp and a multimeter that can measure current. Most "decent" multimeters have a mA (milliamps or thousand'ths of amps) as well as at least one large scale, either 10 or 20 Amps.

Disconnect the battery ground, make sure everything in the car is off, including any LED's (theft alarm?) or other accessories

Insert the 12V lamp in series with the battery to ground. This now becomes a current indicating device. Shade the lamp and see if it glows. This will show that there is a drain.

Pull the trunk light switch if used, check the glove box light, remove the lighter and toss it in the ashtray. Double check that everything is off.

If the glow level has not changed, remove the fuses, one at a time, checking the lamp at each fuse.

Next remove the alternator output wire from the alternator stud and tape it off, and recheck.

If no difference, do you have a stereo amp, or a radio that is hot with key off? If so unhook it or remove it's fuse. If you have a modern radio with a "memory" power wire, unhook that as well.

From here on out, it's a matter of usin' yer noggin and THINKING "what is" hooked up "hot" to the battery. Unhook the battery line to your MSD. Cast a suspicious eye to ANY accessory you've added which may have a hot lead --- GPS/ cell/ other charger? Any added electronics?

If you find something which causes the lamp to go to a very low glow or "seems to" go out, now take your meter. Since the lamp is now not glowing, hook the meter up for the highest AMPS scale for safety, and see if you get a reading. If not, or the reading is nearly "off scale" on the low end, now hook it for ma (milliamps) at the highest ma scale, and see what you have.

If you don't know how to set your meter, post a clear photo of it and the model number, or at least the meter's model number, and we can help you from there.

65s did not have much in the way of mystery safety modules, so there is just not much there.

THE OTHER THING is that you might just have a crappy battery. If you cannot "see" any drain, either with your lamp or meter, CLEAN the top of the battery very well, charge it up and if possible, check it with a load tester AND a hydrometer, and then let it sit disconnected for awhile, and see if it goes down on it's own.
 
Yeah, use a multimeter to check for amp draw. Pull fuses 1 by 1 until draw drops to roughly .05A.... Are you running a voltage gauge ? If so make sure it is wired to a key on circuit. Previous owner of my car wired it up to constant battery voltage and would kill my battery in about 2 weeks also. Just a thought for you..
 
THE OTHER THING is that you might just have a crappy battery. If you cannot "see" any drain, either with your lamp or meter, CLEAN the top of the battery very well, charge it up and if possible, check it with a load tester AND a hydrometer, and then let it sit disconnected for awhile, and see if it goes down on it's own.
This has caused me more headaches than damn near anything in a car. If you have a conventional battery, the kind where you can add fluid to...and have to do so on a regular basis, make sure the top of it is spotless. And check the connections. Not just where they are bolted to the frame or the starter etc. But the cable in the lug. Was chasing an electrical problem for a friend once and the problem was the ground cable was right under a very slow oil leak. The truck had an oem style cable that had the end just crimped on. The oil dripped on to the cable and ran into the lug. If the truck sat for more than a day or 2 the battery was dead. Was not so much that it created a drain but prevented it from getting fully charged. Fixed the leak, made a cable with the end soldered on and covered with shrink tubing, problem ceased to exist.....
 
Are you running a voltage gauge ? If so make sure it is wired to a key on circuit..

...............AND............do ya have a clock? It might not be workin' right. The old originals had a small spring, would for a short time by an electrical contact and solenoid. If that fails, it might be drawing current.
 
67Dart and 65-440 are both correct. When I worked as a dealership mechanic we would attach a test light in series on the ground side of the battery cable between the cable and battery post. If there was a current draw the test light would glow. Then we would start pulling fuses as suggested, or go straight to pulling the main wiring harness connectors at the firewall. If unplugging a fuse or harness connector turned the test light off, then the problem was in that circuit. From there start unhooking whatever is on that circuit to isolate the problem.
A good wire harness diagram, such as a FACTORY repair manual is a must-have, as they will have the correct wire color codes. Books like Chiltons, etc usually have incorrect diagrams/omissions, and/or wrong wire colors.

One day a car came into the shop, blowing some particluar fuse on a regular basis. Unplugging everything on the circuit one by one did not fix the problem, finally with the help of the factory wire diagram found the owner had plugged togther two wires that were for an accessory that the car did not have, but the owner thought should have been connected. Those two wires were not on the circuit that was blowing fuses, but were causing the fuse to blow. Try finding that without a good wiring diagram.
 
Also, any car (especially that old) that is in a wet/ corrosive/ humid environment, check such things as

The routing of the rear harness, which can suffer moisture damage.

Door switches and the lighter socket, which can accumulate wet sludge/ rust/ corrosion that can be conductive. This may not cause much of a drain, but they can cause SOME

It might even be possible that moisture / corrosion has "built" a conductive bridge up in the ammeter
 
An easy solution is a battery tender

I keep my cars on one during the winter, but on some they are on year round.

My gold wing drains the battery, keep on tender except when riding

Finding it might be very difficult, but not impossible
 
From what I read, most new cars have enough parasitic loads to run down the battery in 2 weeks. Airport parking lots routinely jump their customers. Consider your car modern.

I put a Battery Brain on most of my cars (blue box in my Avatar). I like the one w/ remote for anti-theft too. I leave my car at work and bike home so if it doesn't start when I return in the morning, a headache. The Battery Brain has saved me many times. Whenever I had one trip regularly, I had Autozone check the battery and always bad (couldn't hold charge, ...).
 
I donoo, I have an 86, 98 Ranger, and a 95 Olds. One of those routinely sits for more than 2 weeks at a time, like this summer. I was driving the 67!!!! Never had a battery go down.

One of these days, when I have nothing else to do LOL I'll measure the drain on all of 'em and see where we stand.
 
Have same issue recently- something drawing... need to trace/find.
Will be watching for suggestions- never been good w/electrical issues.
 
unless you go to every part with a multimeter?? I try and do the sometimes simple thing- takes time though. Disconnect things one at a time. Put a multimeter on your battery to see current draws. read your meter, disconnect alt. Do over and over for starter, ign switch, etc. If it takes 2 weeks to kill your battery- its low draw- something like a trunk light, door jamb switch, hood light, radio memory, etc.
Some cars were known to come from factory with dead batteries because their trunk/hood light was on because car was trucked at an angle for mercury?? style switches to think lid was open- even though they werent. So even though you dont have that type switch- it still may be a bad switch or bad ground.
Reclean all grounds. Ive even seen a somewhat clean battery post cause a drain.
If all else fails- install a battery disconnect switch inside car under seat or just disconnect battery when not using.
 
Keeping your battery clean helps, too. I've seen more than one that draws voltage through the case.
 
sorry- got here and comp said there was just the question posted- no answers. 67 dart def has it right
 
BILLGRISSOM is correct.

A newer Gm product with RVC charging systems that started on the trucks about 05 although the updated version in 08 is worse and GM cars, some starting in about 04 like the Cobalt will kill a battery in 30 days if not started. It is due to the BCM controlled charging system and the draw only occurs 1-2 twice a day for short periods of time hence the 30 days. The BCM wants to know Battery state of charge and generates a temp current draw, enough to kill a battery in 30 days.

A Chrylser product like a Caliber can kill the battery in 20 days if not started during the time frame.

Also the latest cars are now using a new second "B" BUSS or MID -SPEED BUSS, that controls the power draw of multiple computers. These may take up to 30 mins to stop drawing current after the key is turned off some if you are perfroming a draw test. The BUSS has to go to "sleep" first before you can get a real current draw value.
 
gonna see if I can locate issue- but would this work in the meantime? $24 shipped from Amazon
See there are alot of options pricewise... dont need overkill. May get one for my boat as well.

[ame="http://www.amazon.com/Battery-Tender-021-0123-Junior-Charger/dp/B000CITK8S/ref=sr_1_1?ie=UTF8&qid=1354986304&sr=8-1&keywords=battery+tender"]Amazon.com: Battery Tender 021-0123 Battery Tender Junior 12V Battery Charger: Automotive[/ame]
 

Attachments

  • batterytender.jpg
    26.7 KB · Views: 292
An easy solution is a battery tender

I keep my cars on one during the winter, but on some they are on year round.

My gold wing drains the battery, keep on tender except when riding

Finding it might be very difficult, but not impossible

Battery tender will not work if there is an excessive amp draw. That plug will get so freakin hot, and the green lamp will never illuminate indicating battery is at proper voltage. I bought a tender for mine cause the battery was dying after a week or so if sitting. I thought the plug was gonna start a fire ! Then i found a draw caused by my voltage gauge. Fixed it, now the tender works perfectly .... But i can also leave my car sitting in the garage for a month untouched without a trickle charge on it, and it will fire right up ! Fix the draw then get a tender ...
 
Battery tender will not work if there is an excessive amp draw. That plug will get so freakin hot, and the green lamp will never illuminate indicating battery is at proper voltage. I bought a tender for mine cause the battery was dying after a week or so if sitting. I thought the plug was gonna start a fire ! Then i found a draw caused by my voltage gauge. Fixed it, now the tender works perfectly .... But i can also leave my car sitting in the garage for a month untouched without a trickle charge on it, and it will fire right up ! Fix the draw then get a tender ...

Thought that was the answer I was gonna get... :banghead:
 
If car sits for 2 weeks that is a long time for a battery to sit ... especially if this is a weekend cruiser .... with short weekend drives ... make sure that aftermarket add ons are supplied 15 power where recommended and not 30 power .... if the old school method of test light is no illuminated and ma draw is virutally nothing ... battery tender is the answer... i have same issue and battery tender is the key...
 
If car sits for 2 weeks that is a long time for a battery to sit ... especially if this is a weekend cruiser .... with short weekend drives .....

Not to start an agruement, but i have to disagree with this. If a battery is idle for 2 weeks and will not start the vehicle something is wrong. 2 weeks is not a long time for a battery to not see a charge, especially if there is nothing draining it. Unless we are talking about a battery with many years of life on it, and at that point its probably in need of replacing anyway .. just my 2 cents ! ..
 
Not to start an agruement, but i have to disagree with this. If a battery is idle for 2 weeks and will not start the vehicle something is wrong. 2 weeks is not a long time for a battery to not see a charge, especially if there is nothing draining it. Unless we are talking about a battery with many years of life on it, and at that point its probably in need of replacing anyway .. just my 2 cents ! ..

I agree. And in a 65, it should not take all that long to find. There just isn't all that much IN one of em, and you are USUALLY NOT dealing with anything which is switched with the key. This leaves out the ignition, voltage regulator, and any switched accessories.

GENERALLY only those things which are not through the IGN switch will cause this problem. The only exception would be a bad ignition switch. Now really, how long does it take to reach up in there and yank the connector off the switch?

If the draw does not go away with the switch connector unhooked, the switch and "all that stuff" downstream are of no concern.

Hell, my old Landcruiser used to sit sometimes for TWO MONTHS at a time. I ran an electric pump, jump in, let the pump run, pump the gas about 4 times, and away it went. This rig variously had a 360, 340, and 318
 
-
Back
Top