Battery Dead after Sitting for 3 days. I Found a 3 amp drain.

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
Over the past couple months I have let the truck sit over the weekend and noticed come Monday morning that it's dead. So to troubleshoot I charged the battery and disconnected the negative battery cable and let it sit overnight. Reading with my meter I notice that the voltage went unchanged at 13 volts. Also had the battery load tested at AZ and its good.

Last night I used my multimeter on the 20 amp DC scale and found that I have a 3 amp drain somewhere.

Does anyone know of any common areas to start checking before I spend a lot of time pulling each fuse?

Some of the common areas I have read about include the starter/alternator/TBC 3 fuse?/ HVACB / etc...

Also, if I pull the MEGAfuse that goes to the rear fuse block I believe I will be effectively narrowing down the search to half of the systems.

Much help appreciated.
 

Mark20

Member
Dec 6, 2011
1,630
I'm not sure about the best order of fuse pulling , but isolating the rear fuse block through its mega fuse would cut your starting search in half.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
OnStar is a commonly flaky module that fails to fully go to sleep.

Depending on precisely how you use the ammeter, you may be putting some modules into woken-up mode, not fully asleep, and it's a slightly misleading test. When are you measuring the 3A current? Do you have OnStar?

And the Megafuse only feeds some of the fuses in the rear fuse block. Many of them are not fed by B+ (direct battery voltage full time) but are switched in various modes by the ignition switch. They are located in the rear fuse block for harness convenience, but their power comes from the front fuse block by way of various ignition switch contacts. Just so you all know. It's all in the schematics. There will be a test for mid-terms. :wink:

EDIT: But it's true that the rear ones involved in a parasitic drain from constant battery power will all be connected to the megafuse.
 

gmcman

Member
Dec 12, 2011
4,656
Have you tried the glovebox light, vanity mirror lights, or the under-hood light to see if they don't shut off?

Did you disconnect the under-hood light when you performed the amp draw test?

Have you added any aftermarket stereo goodies?
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
gmcman said:
Have you tried the glovebox light, vanity mirror lights, or the under-hood light to see if they don't shut off?

Did you disconnect the under-hood light when you performed the amp draw test?

Have you added any aftermarket stereo goodies?

I will check the vanity light. My 2005 doesn't have the decontented glovebox or hood light. I don't think any do after 2002 or 2003. I also have an aftermarket Viper RS but it isn't armed atm. I will pull the fuse and disable constant 12V to ignition to be sure.


the roadie said:
OnStar is a commonly flaky module that fails to fully go to sleep.

Depending on precisely how you use the ammeter, you may be putting some modules into woken-up mode, not fully asleep, and it's a slightly misleading test. When are you measuring the 3A current? Do you have OnStar?

Currently I am measuring the 3A right as I connect the meter leads. Yah I know, I know, wait 10 or so minutes before beginning so stuff powers down. I just wanted to see what I got off the bat.

I have Onstar with the autodim mirror. I added that as it came with the manual rearview mirror. I can start with that and also disco the Onstar to see what that does.

the roadie said:
And the Megafuse only feeds some of the fuses in the rear fuse block. Many of them are not fed by B+ (direct battery voltage full time) but are switched in various modes by the ignition switch. They are located in the rear fuse block for harness convenience, but their power comes from the front fuse block by way of various ignition switch contacts. Just so you all know. It's all in the schematics. There will be a test for mid-terms. :wink:

EDIT: But it's true that the rear ones involved in a parasitic drain from constant battery power will all be connected to the megafuse.
Got it.


Ok, so here is what I have preliminarily.

3 A draw with megafuse connected
.66 A draw with megafuse removed
.54 A draw with TBC 1 and megafuse removed
.22 A draw with IPC/DIC and megafuse removed
.08 A draw with TBC 1, IPC/DIC and megafuse removed


Any thoughts? I am still going at it and hopefully find the issue soon. Thanks!
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
Ok I feel like a Schmuck!

So I guess it's fixed, or rather there was no problem to begin with.

As it turned out all I needed to do was leave the meter connected for a whole 25 seconds. I then saw it drop down to 30mA. I could hear the HVAC actuators complete their cycle.

So Bill thanks for the advice. It's 25 seconds. Not 3 minutes or 10 minutes. Just 25 seconds. A very short setup period indeed.

So I guess even though the battery tested good at AZ and it charges and holds a charge when disconnected there must be something wrong with it. My guess is that it's an internal short or something? This battery has been giving me the run-around. Is a 2.5 year old ACDelco known to do that?
 

NJTB

Member
Aug 27, 2012
612
Flemington, NJ
I always tested for parasitic drains with a 12v test light through the negative battery cable. After the initial 'power up', the light should go out. If it lights at all, there is enough of a drain to kill the battery.
My favorite was bad seat belt switches-what a pain in the ass.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
CaptainXL said:
So Bill thanks for the advice. It's 25 seconds. Not 3 minutes or 10 minutes. Just 25 seconds. A very short setup period indeed.
There's still the OnStar module (if not for you then for other people who might find this thread later). It needs to wake up once per minute for a while, then less often, to listen to OnStar to send out the "remote unlock" code. I can imagine a failure mode where the module initially goes to sleep, then wakes up later and fails to go back to sleep. Your battery discharging might be happening down the road from your initial check. Without more instrumentation, those kinds of issues are harder to catch.
 

Denali n DOO

Member
May 22, 2012
5,596
the roadie said:
There's still the OnStar module (if not for you then for other people who might find this thread later). It needs to wake up once per minute for a while, then less often, to listen to OnStar to send out the "remote unlock" code. I can imagine a failure mode where the module initially goes to sleep, then wakes up later and fails to go back to sleep. Your battery discharging might be happening down the road from your initial check. Without more instrumentation, those kinds of issues are harder to catch.

Ya, I had a faulty Onstar unit that developed 2.2 amp draw that would drain the battery in about 3 days. Just fyi...
 

northcreek

Member
Jan 15, 2012
3,310
WNY
CaptainXL said:
Ok I feel like a Schmuck!

So I guess it's fixed, or rather there was no problem to begin with.

As it turned out all I needed to do was leave the meter connected for a whole 25 seconds. I then saw it drop down to 30mA. I could hear the HVAC actuators complete their cycle.

So Bill thanks for the advice. It's 25 seconds. Not 3 minutes or 10 minutes. Just 25 seconds. A very short setup period indeed.

So I guess even though the battery tested good at AZ and it charges and holds a charge when disconnected there must be something wrong with it. My guess is that it's an internal short or something? This battery has been giving me the run-around. Is a 2.5 year old ACDelco known to do that?

I would go to a dedicated battery store for a test.AZ has a basic test that may miss the fault.I just went to my Interstate guy who put a carbon pile on my battery and it tested "weak".I noticed today on a cold WNY morning that it cranks better than it ever did with the 2yr old 800cca (weak)Delco....Mike.

PS Forgot to mention that I replaced the battery.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
northcreek said:
I would go to a dedicated battery store for a test.AZ has a basic test that may miss the fault.I just went to my Interstate guy who put a carbon pile on my battery and it tested "weak".I noticed today on a cold WNY morning that it cranks better than it ever did with the 2yr old 800cca (weak)Delco....Mike.

PS Forgot to mention that I replaced the battery.

Man that sucks. An 800 cca Delco bad after 2 years? Did you get another Delco? The warranty must have been at least 2 years if that wasn't a 60 series. 60 series are only 670 cca.
 

Mark20

Member
Dec 6, 2011
1,630
As I've mentioned elsewhere I had a new battery with a crack in an end cell. Brand new it never started the Envoy with the same oomph as the original. Eventually it gave up the ghost but was replaced under warranty.
 

northcreek

Member
Jan 15, 2012
3,310
WNY
CaptainXL said:
Man that sucks. An 800 cca Delco bad after 2 years? Did you get another Delco? The warranty must have been at least 2 years if that wasn't a 60 series. 60 series are only 670 cca.

The Delco battery had a 30 month warranty but,only to the original purchaser with receipt.In my case it was in my truck when I bought it 11 months ago (in Ohio) so I had to eat the loss.Good news is that I got a 800 cca Interstate blem for $40,I'm lucky to have an Interstate distributor just down the street...Mike.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
Ok.. I have one right down the street too. Will check them out. BTW do you still get a full warranty on Interstate blems?
 

northcreek

Member
Jan 15, 2012
3,310
WNY
CaptainXL said:
Ok.. I have one right down the street too. Will check them out. BTW do you still get a full warranty on Interstate blems?

Capt...I don't know I've bought plenty of them and never had one fail(my tractor blem lasted 4yrs.) although I think that under a year they would just give you another blem.At $40 I could buy 3 for the price of 1 non-blem so it's a no brainer for me:thumbsup:..Mike.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
northcreek said:
Capt...I don't know I've bought plenty of them and never had one fail(my tractor blem lasted 4yrs.) although I think that under a year they would just give you another blem.At $40 I could buy 3 for the price of 1 non-blem so it's a no brainer for me:thumbsup:..Mike.

I went to Costco and bought the Kirkland battery made by Johnson Controls. Yes it was $80 but I called the local Interstate distributor and they said that the blems only have a 6 month warranty which didnt seem fair to me.

The Kirkland batteries are 3 year 100% and 100 month prorate which from what I hear is supposed to be the best.

Now my truck starts up at warp speed with the 800 cca.
 

northcreek

Member
Jan 15, 2012
3,310
WNY
CaptainXL said:
I went to Costco and bought the Kirkland battery made by Johnson Controls. Yes it was $80 but I called the local Interstate distributor and they said that the blems only have a 6 month warranty which didnt seem fair to me.

The Kirkland batteries are 3 year 100% and 100 month prorate which from what I hear is supposed to be the best.

Now my truck starts up at warp speed with the 800 cca.

I hear ya...my upbringing won't allow me to pass up a deal:wootwoot:...Mike.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
Crap.... damn thing is draining my battery again. I let the envoy sit over the past 4 days and when I went to check the battery today it was at 11.6 volts. Any thoughts? I think I am going to disconnect the alternator and see what that does. I've heard that bad alternators can drain the battery.
 

NJTB

Member
Aug 27, 2012
612
Flemington, NJ
Yes, alternators have diodes (one way electrical check valves) in them and if one goes bad it will drain the battery. A bit rare, but it does happen.
 

mrphoenix80

Member
Jan 1, 2013
251
When I do draw tests at the shop I set my meter to save the min/max reading and leave it sit for a couple hours to watch it. I dont watch it like a hawk however. I just check on it every so often. The acceptable draw is around 22mA max. I connect a jumper wire to the negitive terminal of the battery and the neg cable leave it connected for a minute bypassing the meter and then remove it. This allows things like the dome lights to go off. Then I measure the amp draw if in the milliamps I switch to mA scale again connecting the jumper wire so the modules keep power during the switch over. Then measure your mA draw.

The older onstar modules (up to Gen 6 I think?) are analog and power up for 1 min out of every 10. In GM school we used a Lesabre and it was on the 8's but I don't know when the TB's come on. It only does this for 48hrs to listen for an incoming call from onstar for the remote features. After that Onstar can't help you if your locked out! The newer Onstar modules are Digital and don't power cycle as the draw is so low in standby mode it will not matter. Then after 48 hrs they shut off. Because Onstar has upgraded their systems to digital your old onstar module will not connect anyway. You have to get the trucks hardware upgraded if you want onstar to work again. SO I think you can unhook it safely the part I am unsure about is if it will set codes in other modules saying its missing but it should not effect the operation of the truck.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
Pulled the 10 amp onstar fuse and will see what that does overnight. Voltage is at 12.7 right now and shouldn't move much over the next 12 hours if my suspicions are correct. I've got the dual analog and digital onstar and its been working well.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
Still working on it folks. Battery voltage was 11.4 volts letting it sit over two nights.

I took the Costco battery out cause I didn't want it to run down and sulfate it. Which means yeah, I put the ACDelco back in.

Kind of back to square one here. I took the Onstar mirror out and put the original back in. No change. So I put the autodim mirror back in. Pulled the 10A fuse for Onstar again and we will see what that does.

I think the next step is just to pull the megafuse and see if that keeps it from draining. Then reinstall the megafuse and remove one half of the fuses in the rear box. etc...etc This is a nightmare.
 

gmcman

Member
Dec 12, 2011
4,656
Well, if it were me, I would pull the ECM fuses last but at this point just pull all of them one by one and see what happens.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
gmcman said:
Well, if it were me, I would pull the ECM fuses last but at this point just pull all of them one by one and see what happens.

Eventually I will do that. But right now I want to isolate the problem to either the front or rear fuse box. The main reason for this is because I have a Viper remote start that is suspect and it is connected to constant power up front. That would be another hassle dealing with that and proving it to the shop that installed it. Just don't want to go down that road if I don't have to.
 

gmcman

Member
Dec 12, 2011
4,656
CaptainXL said:
I have a Viper remote start that is suspect and it is connected to constant power up front.

Any chance of measuring draw from this without altering the install or splicing wires?
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
gmcman said:
Any chance of measuring draw from this without altering the install or splicing wires?

Sure, I could pop open the underside of the drivers side dash and look in there and see which wire they spliced into. But along with the controller, relay satellite and bypass module there are a ton of wires up in there. Also have an ebrake controller for the trailer. I'm confident I could find the points were they tapped into for power but because I got the remote start in March it's still under warranty and I don't want to accidentally pull anything apart. Pretty much already can guess where they tapped into. More than likely the ignition +12 red wires which are constant.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
Update Time...

Yesterday I charged the battery in the vehicle and let it sit overnight. I had all the IGN fuses removed and also the trailer and Onstar fuse removed. I was pretty confident at the rate of .01 volts per hour drain that I was getting that it had to be one of these circuits.

Last night I removed the hush panel and IPC to check on the wiring job the shop did for my remote start. Everything looked good. There was some nice butt connections made and everything appeared to look in order and zip tied well. So then I decided to commence double checking my work after replacing the ignition switch aa while ago and check the tooth placement and how it was indexed. I got online and looked up some articles and reindexed it. I then buttoned everything back up.

After reconnecting the battery I said to myself "screw it" so I put all the fuses back in and hoped for the best.

Well I am glad to announce that after all that time it appears that my voltage is holding steady over the past 16 -20 hours. It is at 12.88 volts. A couple days ago it would have been at 12.3.

I really hope that the ignition switch was it. It got bitter cold last night (12 F) and the battery voltage hasn't budged.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
I got a break last night with this pain in the arse troubleshooting. To say this has been time consuming is an underestimation.

So ultimately I found out that the drain wasn't caused by the ignition switch. I went to charge my cell phone today with the cigarette outlet and my phone never charged. So I went under the hood trying to figure out if there was a fuse blown. Sure enough the 12 volt accessory fuse was blown. Put a new fuse in and the battery started to drain again. .01 volts per hour.

On the up side the battery has been holding a charge over the past few days with that fuse blown which means that is the problem circuit. I guess the first place to look is the panel and check each socket. Sounds easy but it could be the second row outlet as well. Might end up having to take my whole center console out just to fix this. Arghhh!

I brought my Costco Kirkland battery back today and got 100% cash back. Still had the old ACDelco sitting around and using that again since it's not the problem. Drove around town for an hour today and got home took a reading and the battery is at 12.9 volts.
 

CaptainXL

Original poster
Member
Dec 4, 2011
2,445
gmcman said:
Any chance of measuring draw from this without altering the install or splicing wires?

I was still having the draw problem over the past month. Kept the battery alive on a charger as needed. So I removed the Viper remote starter and the XK01 bypass module yesterday and found that the bypass module is the cause of the drain. Battery voltage has been 12.50 volts and holding over the past 24 hours. Now I just need to have the bypass module looked into by my installer.

I could have saved myself a whole lot of time and trouble if I would have just taken a logical approach to all this troubleshooting and removed the remote start at the beginning. It was the last thing added to the vehicle back in March of last year. In classic fashion I always assume the problem is more complicated then it really is.
 

Forum Statistics

Threads
23,273
Posts
637,499
Members
18,472
Latest member
MissCrutcher

Members Online