Battery Drain... need suggestions
Thread Starter
Burning Brakes
Joined: Nov 1999
Posts: 790
Likes: 0
From: Flanders NJ
Battery Drain... need suggestions
I need eventually to tackle my battery drain problem that has existed on my '79 since the day I purchased it. I installed the shutoff valve that I use constantly when the car will sit for more than a few days. For a non-mechanic like myself, what is a simple way to identify what accessory is the culprit when the car sits that drains the battery down. In Cold weather below 40 degrees or so it will drian in a matter of days. When it's 70 degrees or above it can easily last over a week and still start. By the way, the battery has been replaced and checks out as good.
thanks...
thanks...
Instructor
Joined: Jul 2002
Posts: 110
Likes: 0
From: sarasota fl
Re: Battery Drain... need suggestions (Tom T)
unhook the negative lead on your battery.clip a test light on the the negetive CABLE(make shure it is disconected from the battery)touch the other end of the test light to the positive post on your battery.if the test light lights up you have a draw.as you are doing this have someone else remove and replace each fuse on your fuse panel one at time.when the fuse is removed that makes the test light turn off,that is your circuit with the draw.now you can trace that circuit for the problem.hope this made sense to you.
Racer
Joined: Mar 2001
Posts: 327
Likes: 0
From: Southlake, Texas, USA
Re: Battery Drain... need suggestions (Tom T)
Disconnect the ground and attach a test light to the ground cable and the post. It you have a draw the light will come on.. Then remove the fuses (one by one) and watch the light. When the light goes out that is the circut that the draw is on.. Look for the clock.. That tends to be the culprit.. Hope this helps!!
Le Mans Master
Joined: Apr 2001
Posts: 5,000
Likes: 1
From: Minneapolis, Mn USA
Re: Battery Drain... need suggestions (SprintCarDriver)
Most cars will have some continous draw due to clocks etc.. and now computers.
The light method is a good place to start, but I would use a DMM Digital Multimeter instead of a light.
Position the DMM at the battery negative connection to the negative wire disconnected and put the DMM on 10Amp DC current switch setting/wire set-up and connect it between these 2 points. You may get a reading which could be in the few hundread milliamps, which is probably excessive current flow. You probably want to see something closer to 50ma or even less. If you do not get a reading with this, then set it up on the 2 Amp scale setting, which will me more accurate. 1000milliamp = 1Amp
If your problem is occuring with the key on the off position, then leave it there.
Start disconnecting fuses to see if this reading drops considerably. Use this to isolate down to your area. The DMM is just a more accurate tool than the light, but the method is the same. Like all the others said, good luck.
Another place to look is your alternator. There could be a internal problem there causing this too.
Brent....
The light method is a good place to start, but I would use a DMM Digital Multimeter instead of a light.
Position the DMM at the battery negative connection to the negative wire disconnected and put the DMM on 10Amp DC current switch setting/wire set-up and connect it between these 2 points. You may get a reading which could be in the few hundread milliamps, which is probably excessive current flow. You probably want to see something closer to 50ma or even less. If you do not get a reading with this, then set it up on the 2 Amp scale setting, which will me more accurate. 1000milliamp = 1Amp
If your problem is occuring with the key on the off position, then leave it there.
Start disconnecting fuses to see if this reading drops considerably. Use this to isolate down to your area. The DMM is just a more accurate tool than the light, but the method is the same. Like all the others said, good luck.
Another place to look is your alternator. There could be a internal problem there causing this too.
Brent....
Thread Starter
Burning Brakes
Joined: Nov 1999
Posts: 790
Likes: 0
From: Flanders NJ
Re: Battery Drain... need suggestions (MN-Brent)
Thnaks everyone for the quick replies...
Brent - Not sure about a DMM Digital Multimeter??? Remember I'm a non-mechanic.
Where do I get one of those & are they expensive?
Brent - Not sure about a DMM Digital Multimeter??? Remember I'm a non-mechanic.
Where do I get one of those & are they expensive?
Le Mans Master
Joined: Apr 2001
Posts: 5,000
Likes: 1
From: Minneapolis, Mn USA
Re: Battery Drain... need suggestions (Tom T)
Tom
You can get a DMM at any tool store and they range from some cheapies for $20 to pretty expensive $100s +
This is usually a hard problem to isolate, even if you get it down to a fuse circuit which is causing this. Ive done this on a few different vehicles and due to auto wiring diagrams not being so great, its a real PITA, even with my electronics background.
The GM service manuals are probably the best wiring guides that I have seen and even have electrical troubleshooting help set-up. Using these will get you a lot closer than a Chiltons or Haynes manual will.
Brent-Application Engineer :conehead
You can get a DMM at any tool store and they range from some cheapies for $20 to pretty expensive $100s +
This is usually a hard problem to isolate, even if you get it down to a fuse circuit which is causing this. Ive done this on a few different vehicles and due to auto wiring diagrams not being so great, its a real PITA, even with my electronics background.
The GM service manuals are probably the best wiring guides that I have seen and even have electrical troubleshooting help set-up. Using these will get you a lot closer than a Chiltons or Haynes manual will.
Brent-Application Engineer :conehead
Melting Slicks
Joined: Jan 2000
Posts: 2,386
Likes: 3
From: far, far away
Re: Battery Drain... need suggestions (Tom T)
On my '81, I had that problem for long time, damnear drove me nuts. Finally discovered it was the "courtesy lamp time delay module". :rolleyes:
You know, that gizmo that makes the interior lights stay on for 30 or 40 seconds after you close the door. The blasted thing would turn my lights on and off at random all the time, sometimes leaving them on for hours at night. Solved the problem by disconnecting it; after a year or so (my wife complained about no interior lights) I bought a new module. About $45 from Zip.
The lights on your '79 work the same way, I think. The module on your car should be behind the glove box, on the right side. It's maybe 3"x2"x1/2" or so. Mine was orange plastic, and was somewhat scorched and melted.
I think the advice given by the other guys is good, and I'd check that first. But if it's the timer module, that won't show up in the test they suggested, because it only sucks the battery dry when you're not looking! :(
[Modified by Gator81, 4:32 PM 11/6/2002]
You know, that gizmo that makes the interior lights stay on for 30 or 40 seconds after you close the door. The blasted thing would turn my lights on and off at random all the time, sometimes leaving them on for hours at night. Solved the problem by disconnecting it; after a year or so (my wife complained about no interior lights) I bought a new module. About $45 from Zip.
The lights on your '79 work the same way, I think. The module on your car should be behind the glove box, on the right side. It's maybe 3"x2"x1/2" or so. Mine was orange plastic, and was somewhat scorched and melted.
I think the advice given by the other guys is good, and I'd check that first. But if it's the timer module, that won't show up in the test they suggested, because it only sucks the battery dry when you're not looking! :(
[Modified by Gator81, 4:32 PM 11/6/2002]
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Safety Car
Joined: Jan 2001
Posts: 4,660
Likes: 3
From: South Central Louisiana
St. Jude Contributor
Re: Battery Drain... need suggestions (Gator81)
On my '81, I had that problem for long time, damnear drove me nuts. Finally discovered it was the "courtesy lamp time delay module". :rolleyes:
You know, that gizmo that makes the interior lights stay on for 30 or 40 seconds after you close the door. The blasted thing would turn my lights on and off at random all the time, sometimes leaving them on for hours at night. Solved the problem by disconnecting it; after a year or so (my wife complained about no interior lights) I bought a new module. About $45 from Zip.
The lights on your '79 work the same way, I think. The module on your car should be behind the glove box, on the right side. It's maybe 3"x2"x1/2" or so. Mine was orange plastic, and was somewhat scorched and melted.
I think the advice given by the other guys is good, and I'd check that first. But if it's the timer module, that won't show up in the test they suggested, because it only sucks the battery dry when you're not looking! :(
[Modified by Gator81, 4:32 PM 11/6/2002]
You know, that gizmo that makes the interior lights stay on for 30 or 40 seconds after you close the door. The blasted thing would turn my lights on and off at random all the time, sometimes leaving them on for hours at night. Solved the problem by disconnecting it; after a year or so (my wife complained about no interior lights) I bought a new module. About $45 from Zip.
The lights on your '79 work the same way, I think. The module on your car should be behind the glove box, on the right side. It's maybe 3"x2"x1/2" or so. Mine was orange plastic, and was somewhat scorched and melted.
I think the advice given by the other guys is good, and I'd check that first. But if it's the timer module, that won't show up in the test they suggested, because it only sucks the battery dry when you're not looking! :(
[Modified by Gator81, 4:32 PM 11/6/2002]
Instructor
Joined: Jun 1999
Posts: 112
Likes: 0
From: n.h.
Re: Battery Drain... need suggestions (Tom T)
yup,,,,,,,,same thing on my 77....that dadburned curtsy lite thingy......after messing with the door switches for hours to make sure they where ok,that things was doing it..
Melting Slicks
Joined: Jan 2000
Posts: 2,386
Likes: 3
From: far, far away
Re: Battery Drain... need suggestions (Peter Bilella)
The module on your car should be behind the glove box, on the right side. It's maybe 3"x2"x1/2" or so. Mine was orange plastic, and was somewhat scorched and melted.
I believe this module was introduced into the wiring harness with the '78 model. Early '78's have the module on the driver's side, under the dash, by the steering column. Late '78's, through '82's, have it behind the glove box, on the right. :seeya
Pro
Joined: Jun 2000
Posts: 569
Likes: 0
From: phoenix az
Re: Battery Drain... need suggestions (74jack)
i had this problem with mine. It turned out to be the light in the storage compartment behind the seat. The door was warped just enough to release the plunger and leave the light on. It took a few days to drain and it drove me nuts.
Drifting
Joined: Jan 2002
Posts: 1,453
Likes: 2
From: Toronto
Re: Battery Drain... need suggestions (BubbaJJ)
i had this problem with mine. It turned out to be the light in the storage compartment behind the seat. The door was warped just enough to release the plunger and leave the light on. It took a few days to drain and it drove me nuts.
