Printer Friendly Forum Posts - battery being drained what can i do?

hello, everyone,

i have a 2001 chevy tahoe.

something is draining my battery and i have no clue what it is

does anyone know how i can isolate the problem, or what i have to do in order to test to find the draw.

it can be anything from an accessory i installed to the actual things that came factory with the truck.

please help.

any and all tips and ideas are appriciated.

thank you

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do you have a dmm? if you do you can measure for parasitic current drain. the drain on your battery from clocks, computers, and security systems when your engine is off? I'm assuming thats what your talking about? parasitic loads typically run 20 to 30 milliamps.
to take such measurements disconnect your neg battery cable placing your dmm set for amps dc between the disconnected cable and battery post without the engine running. read the meter and take note of the current measurement. begin removing fuses one at a time until the current measurement lowers. you have now identified the offending circuit. you mentioned you installed accessories. you can use this method to test powered up accessories provided their current draw doesnt exceed what the meter is fused at (commonly 10amps) otherwise you'll blow the meters fuse. next step would be to inspect the wiring of the offending circuit. if the wiring checks out good, now you need to inspect the electrical component/s. and proceed from there.
hope that helps!

hey where did that extra question mark come from? oops!

so place the dmm in the line of the negative cable?

thanks i really appriciate it i will do this tommorrow, it is too dark out now :(

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correct. now if after pulling fuses you dont identify the offending circuit, you likely have a short somwhere else. but pull the fuses first.

haven't had a chance to do it yet, hopefully the weather will be nice tuesday. i will post back up what happens...i hope this finds the draw.

i tried the dmm on the positive side and the ground side and the meter read nothing, i checked the meter to make sure it was on the correct settings and it was.

then i tried the test light in line with the positive side and it lit up. so i started pulling fuses and it still stayed on then i disconnected all me stuf fand my alarm and it still was on.

i am so confused :(

the only thing that bothered me was that my truck has 4 or 5 different ignition fuses, 2 of them are maxi fuses under the hood, which when i pulled the fuse out and tested each side they were both hot even though the car was off.

the other little fuses did not have power untill the ignition was turned on.

i spoke to someone and they told me the reason why both of the others have power is because of a short somewhere and that would cause that to happen.

does this give anyone any ideas i am dumb founded.

any ideas why the meter did not read anything but the test light lit up?

i appriciate all ur time and help

Make sure that your meter is set for DC amps, and the leads are in the correct location on the front of the meter...if your meter's like mine, it's got a separate terminal for measuring amperage.

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C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two

Exactly. Where the probes plug in at the bottom, the red one will probably have a seperate terminal it needs to be plugged into labeled for amps or current.

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My ex once told me I have a perfect face for radio.

first determine if your meter's fuses are good. with your meter set for ohm's and the red lead in the ohm/volt socket insert the pointed end into the amp socket. if your fuse is good you'll read apx. 0 ohms. if your fuse is blown you will not get a reading (open circuit). replace the fuse if need be. when taking unknown current measurements make sure you're using the highest scale possible (10 amps in this case).

Ok, First disconnect the negative terminal of the battery. Then make sure all your doors are closed and ALL LIGHTS ARE TURNED OFF( if you don't you will blow the meter's fuse). Set your meter to mA and place red lead in the appropriate place (I do mean mA if you don't then your meter may not give you an accurate reading). Place red lead on the ground from the car. Then place the BLACK/ com lead on the battery's ground. Leave it sit for 30 minutes to allow the vehicle's computers to go to sleep. If the reading is above 50mA then according to GM there is a parasitic power draw. At this time start pulling fuses.

Take note of the reading before the computer goes to sleep and after 30 minutes. If the number is the same then there is something keeping the computers on and that is your problem. Anything that tries to draw power from any wire that would normally shut down would cause this.

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Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

i am using a FLUKE 77 III meter. i am 100% sure that i put the meter connections on the correct end of the meter i even double checked for that cause sometimes i do over look that.

i think maybe the fuse is blown, or i was impatient and did not wait a while, i put the meter on and waited like 5 minutes and there was no reading. i will try the 30 minutes and see if that works

i will try this again today or sunday and post back.

thank you for all your help :)

Red probe goes in the 10amp terminal and the black probe goes in the com terminal...make sure the meter is set to dc Amps. If it still isn't working chances are the fuse is blown inside the meter...take the cover off and there will be 2 glass tube fuses inside on is for the 10 amp terminal. While doing this test, like mentioned, positive battery terminal needs to be connected and the negative off, your meter goes inline with the negative terminal and post and make sure everything is off, even the under hood courtesy light.

i checked and the fuse for the meter was blown. i can't seem to find them anywhere though.
does anyone know were i can pick them up the models are

BUSS FUSE DMM-44/100
and
BUSS FUSE DMM-11A

they are for the Fluke 77 III meter

Damn they are expensive. Outpost.com (fry's electronics) has them.

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Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

I'm having a similar problem. I can check my battery in the morning and it'll read around 11.80 to 11.90. I can drive the car and park it and check, it'll read 12.24 or so. If it sits for 2 days it'll read lower, around 11.70. The longer it sits, the lower it'll read. I know something is drawing power when the car is off. How do I determine what it is? This has been going on for quiet some time and I've been looking. I can't seem to pinpoint what is causing this to happen.

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'85 Toy

Another question, if I charge that battery and remove the positive cable and leave it off for a couple of days, shouldn't it still read over 12 volts?

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'85 Toy

a charged battery at rest will read apx. 12.66 volts.

sexyvic1 wrote:

i checked and the fuse for the meter was blown. i can't seem to find them anywhere though.
does anyone know were i can pick them up the models are
BUSS FUSE DMM-44/100
and
BUSS FUSE DMM-11A
they are for the Fluke 77 III meter

I get my Fluke fuses from Lowes and Home Depot.. but they are still around $5.00 each. That's why I use a cheaper meter (with cheaper fuses) to measure current.

Jim

i went to radio shack and home depot and i got no luck with the fuses. i will check lowes today.

i hope they have it.

thanks guys, i will keep u guys posted on the truck after i get the fuses.

Supradude,

read the first part of this topic and it'll tell you how to find the culprit. Basically you read current draw, then pull fuses one at a time until you find the problem.

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My ex once told me I have a perfect face for radio.

Thanks, I tried leaving the meter on for close to an hour today and I never noticed any draw. I'm wondering if it might be my battery. Or maybe a problem that "surges" every once in a while that isn't a constant drain?

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'85 Toy

what about on the face of the dmm its confusing on some? For instance set the dmm to DC mA but .5, 50 or 250 DC mA Then on a real cheap one we got its has DC 0-50-100-150-200-250 then right below it it has 0-10-20-30-40-50 but no label i assume that the 0-10-20-30-40-50 are mA correct. kinda confusng

Snapper

Supra,

when measuring for current draw, make sure your leads are plugged into their respective slots on the multimeter. Many times the positive lead will need to be plugged into a different slot for current than for voltage. Sometimes you'll have more than one current slot/setting. Start out on the highest scale, and work your way down until you can get an accurate reading. If you're doing all this, and notice no major issue, only normal draw, I'd check the battery. 11.7 at rest is not where it should be- check the fluid levels and if they're okay, I'd replace the battery. When you first turn off the engine, you'll notice a higher than normal voltage, then after it sits a few minutes, it will level off and you should have at least 12.6 volts.

Snapper,

you are correct, a cheap multimeter will read in mA. More expensive ones will measure up to 10 amps. Clamp type meters can measure much more since they only sense current, and are not connected in series.

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My ex once told me I have a perfect face for radio.

ok fellas

i found the short in my tahoe. ( my meter's fuse's were blown, i used my friends meter and it worked )

as soon as i connected the meter it read 145.5 mA , the it droped to 115.5 mA , then it finally came to a rest at 44.9 mA.

i pulled the alarm and it automatically went down to 14.60 mA i found which wire it was is the alarm and pulled the fuse for it.

is 14.60 mA a good resting point or is there something else still drawing?

the alarm i have is the autopage RS-850LCD

the problem wire was on a 5 pin white plug.

it was the RED wire that has a 3amp fuse on it. it controls the system 12 volt power / constant and is also connected to RED w/ WHITE stripe wire which is the Parking Light Relay Power Input.

now do u guys think this is something i can fix, or is it internal and i should send the brain back to autopage ?

thanks for everyones help i really appriciate it alot posted_image

Geepherder, I have a Wavetek model #CDM600 ac/dc clamp-on multimeter also. Would this be better to find the problem with? I've tried it set on dc at 200A and haven't seen it move from zero also.

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'85 Toy

Vic, that draw sounds reasonable, but you can contact Autopage to ask them the spec or it may be listed in your manual somewhere.

Supra, a clamp on meter is best suited for higher current applications (a few amps or more)- just look at the scale you set it on- 200 amps. If you're sure you have the leads connected properly, check for the internal fuse. The radio and some other electrical components that use constant power have a continuous draw (however so slight) that can be measured with a multimeter. Cheap meters many times only measure up to a couple hundred mA, so if you had a door open, or the light under the hood was on, the internal fuse would easily blow when you tried to measure current.

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My ex once told me I have a perfect face for radio.

The 200 amp setting is the lowest one on this meter. I can clamp it on the power wire going to the amp and turn the radio on and it reads 4.2. I guess I'll try the Fluke meter again and see what I can find with it. This is getting very frustrating!!!!

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'85 Toy

That's exactly my point- it's not meant to take very small measurements- in the mA.

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My ex once told me I have a perfect face for radio.

i called autopage and told them the problem and the tech said to send in the brain. i asked him how and he said that i would have to go back to were i purchased it from and they would have to return it.

what B.S. he said that they do not deal with consumers. i told him i am willing to pay for the repair i just want it fixed and he said it doesn't matter they will not accept it.

so know i gotta find a dealer ( there aren't any near by me ) to send the unit in.

last time i buy autopage.

i had DEI in my grand cherokee and the brain had gone bad the DEI people accepted it from me fixed it for free and sent it back all within a week of when i sent it. i guess thats the way to go from know on.

geepherder : when u said the draw is reasonable did u mean for the 14.60mA draw?

thanks buddy?

I meant the 45 mA total doesn't sound bad- what kind of draw did Autopage say the alarm should have?

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My ex once told me I have a perfect face for radio.

I think the problem is the battery. I swapped batteries with my Dad and ever since I did I can check even after 48 hours and it still reads 12.4, doesn't drop like it was doing with my battery in the car. Mine would drop to around 11.8 after 48 hours of sitting. Now the problem I face, Advance Auto probably won't give me another one, since it doesn't completely DIE, just slowly fades away. It must be a cell going bad, just not completely gone bad yet. It's only a little over a year old and it's the best line they sell. Any advice?

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'85 Toy

I'd take it back and explain the situation. Tell them the kind of problem you're having, and what you've tried so far to identify the battery as the culprit.

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My ex once told me I have a perfect face for radio.

call around and see if any shops in your area have a digital( good quality) battery tester, it will show the battery fault, then take it to them and bring the battery and the bill to your parts supplier...good luck

Yeah, 45mA isn't that bad. If your battery is going dead in short period of time off of that then your battery is going bad.

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Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

Just wondering, will vinegar finish off a weak battery?

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'85 Toy

If not, what will?

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'85 Toy

What did they say when you took it back?

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My ex once told me I have a perfect face for radio.

They charged it up for 2 hours, then ran some type of tests on it and it came up "good". I tried to explain how I had been checking it compared to the other battery I was using and the difference in the volts after it sits for a few days, but they just want to go by that machine.

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'85 Toy

k guys, i got the alarm back from autopage and they said there was nothing wrong with it.

i don't understand because while the alarm was out to them, the car sat for over 2 weeks and the battery didn't die. so it makes me think the alarm is the problem.

the autopage tech said it may be the passlock from dei 555L . he said that the blue with white wire might cause the battery to die.

i checked that wire with the car and alram not armed and it read 11.94volts. i went out and bought a new one and the new one read 11.91v

any ideas?

also under my hood in the fuse box the iggnition fuse has power on both sides??? even when i pull the fuse out i have power on both sides.....that can't be right because if there is power on both sides then there wouldn't be a fuse.

any ideas on this too?

i am so agrivated, all of this happened while the car sat for 3 weeks in my garage. i feel like burning it down but i have so much labor into it :o(

Did you replace the battery like was suggested before? If that's the problem, then even a small (normal) constant drain such as the alarm could cause it problems.

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My ex once told me I have a perfect face for radio.

geepherder wrote:

Did you replace the battery like was suggested before? If that's the problem, then even a small (normal) constant drain such as the alarm could cause it problems.

yes i have 2 brand new optima yellow tops.

Okay, so you're using 2 batteries. If you disconnect them both and take voltage measurements of each, is one significantly higher than the other? If so, this could be your problem.

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My ex once told me I have a perfect face for radio.

sorry i forgot to mention before, i only have one battery in at this time, he 2nd is just for my audio and accessories, which i dissconnected everything and took the battery out.

there is no line even going to the 2nd battery right now.

so basically it is like haveing a single battery.

i also have a midtronics battery load tester which i did use on the battery thinking it may be the problem but the battery is mint.

i really think it is something with the alarm though.

cause when the alarm was out to repair the truck never lost power, i am so confused

Well, 44 mA is a perfectly acceptable constant draw. Did you have this problem with the original battery, too? How do your cables/ends look? How about your grounds? One other thing- when you vehicle doesn't start, what is the voltage reading at the battery? If it looks okay, it may be your starter.

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My ex once told me I have a perfect face for radio.

yes i did have it with the original battery, it actually killed it thats why i went out and bought new ones, i thought maybe the old batteries were the problem.

as for the wiring it is all mint i ripped everything out and i still had the problem :o(

any idea why this may be: under my hood in the fuse box the iggnition fuse has power on both sides??? even when i pull the fuse out i have power on both sides.....that can't be right because if there is power on both sides then there wouldn't be a fuse.

i think that may have something to do with it but i don't know what would cause that, one person said that if there is a short in the truck that could happen but i checked everything.

i am so lost and upset. i put a ton of money and time into the truck and i can't even drive it. it has been liked this since the end of october.

As far as your fuse question, is this with the key off as well? If not, you may have the secondary ignition circuit backfeeding to the primary (or vice-versa) through the ignition switch. That's about all I can think of.

How do your fluids look? Slap me if you think I'm silly, but I read that if you let your coolant go (don't flush it at normal intervals, etc.), it becomes acidic, and actually acts becomes a battery with your car. That can cause big problems, which are hard to pinpoint.

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My ex once told me I have a perfect face for radio.

so the battery tests good, and the parasitic load is normal, that leaves the alternator. check your alternator. with your engine at idle your battery should read 12.6 volts while under load (headlights, audio system, air conditioning, wipers, etc.) next increase your engine rpm's to around 2000 rpm's and the voltage at the battery should go up to apx. 13.8 volts or higher and stay there with increased engine rpm's. if the voltage doesn't increase with an increase in engine rpm's from idle your alternator is bad. with a bad alternator your battery doesn't fully charge and any parasitic load on the battery at rest will further deplete its state of charge.

geepherder: i have that ignition fuse problem with the car off no key in at all.....the fluids are all perfect ( intresting to know that about the fluids, i will definatly keep any eye on that with future cars)

i pulled the entire fuse box out yesterday and started testing the actual fuse board to see if that was at fault. i did continuity tests across the terminals with the fuses out and there was no continuity, so i came to the conclusion that the fuse box is good. only when power is contected to the fuse box, i get power on both sides of the fuse

i think something is backfeeding to it like u said but i don't know what posted_image

electrostatic: i thought of the alt too but so i have checked the alt and it is working perfect no problems at all.

p.s. i would like to thank you guys for taking the time out and try to help me. all your ideas are helpful and i hope u have more untill i fix this problem.

things aren't adding up!

no...thats why i am sooo upset, i have had friends and neighbors all come by and look to see if maybe i am missing something but nobody knows...they all see everything i see.

somethings being overlooked but WHAT ? posted_image

the truck only has 22 thousand miles on it.....it is like brand new.....i hardly drive it, and since this has happened ( october ) i haven't driven it once....just in and out of the garage to work on it.

hey guys i think i may have figured it out but i need a little more help.

i posted what i found under the alarm section of this forum here is the link can u guys please read it and see if u can help. i apologize because it is a bit long but i sincerely do appriciate all of your time and help.

https://www.the12volt.com/installbay/forum_posts.asp?tid=75589&PN=1

THANK YOU GUYS AGAIN