Battery Drain 2008 Chev

[downslope]

The battery on my 2008 Chevy 3500 6.0 has been running down if I leave it parked for few days. The battery is about 3 years old, so at first I suspected that. But it seems to take a proper charge (takes 8 hours at 4 amp) and is OK if I use it every day or even every other day.
So today I put an ammeter in the positive cable line with everything turned off and key removed. It showed approx 3 amps and made a little spark when touching the probes. So I am thinking this indicates a problem, but where do I start? Disconnected the 2nd auxillary battery, it still read 3 amp on the starting battery. Tried pulling a few fuses, like Integrated brake controller, backup lights, running lights, some of the trailer light fuses (no trailer connected) but no luck, still shows 3 amp draw.

Any suggestions where to start diagnosing? There are like 70 fuses and circuit breakers, many with cryptic labels for things like AC, ECMs, FI, ABS, etc, etc. I started with the lights because it has those lights with delayed shutoff for when you get out of the truck in the dark it keeps backup lights and cab lights, running lights lit for a while. Could one of the solid state controllers be drawing power somehow? It's a basic work truck, so no power windows, locks, mirrors, defrosters, etc.

Any of you ever have a problem like this? Truck has less than 40K mile.

 

[k0ua]

The battery on my 2008 Chevy 3500 6.0 has been running down if I leave it parked for few days. The battery is about 3 years old, so at first I suspected that. But it seems to take a proper charge (takes 8 hours at 4 amp) and is OK if I use it every day or even every other day.
So today I put an ammeter in the positive cable line with everything turned off and key removed. It showed approx 3 amps and made a little spark when touching the probes. So I am thinking this indicates a problem, but where do I start? Disconnected the 2nd auxillary battery, it still read 3 amp on the starting battery. Tried pulling a few fuses, like Integrated brake controller, backup lights, running lights, some of the trailer light fuses (no trailer connected) but no luck, still shows 3 amp draw.

Any suggestions where to start diagnosing? There are like 70 fuses and circuit breakers, many with cryptic labels for things like AC, ECMs, FI, ABS, etc, etc. I started with the lights because it has those lights with delayed shutoff for when you get out of the truck in the dark it keeps backup lights and cab lights, running lights lit for a while. Could one of the solid state controllers be drawing power somehow? It's a basic work truck, so no power windows, locks, mirrors, defrosters, etc.

Any of you ever have a problem like this? Truck has less than 40K mile.

Pull the connections to the alternator to see if that could be the trouble.. You are going about it the right way, just keep pulling circuits and keep watching the meter.. 3 amps is a bunch.

 

[davesl708]

I would start with the ground wires. That has been my nightmare chasing down all the ground lugs and getting them tightened back up. There is one under the dash that requires all the dash to be removed to get to it.

As to diagnosing put a amp meter on the positive cable and pull fuses one at a time. You may find the problem moves around. That is what indicated to me it was the ground wire. GM will be no help in locating them either.

 

[Looking4new]

I would disconnect the alternator first, that may be the source of your problem. Then like the others have said, one fuse at a time. Your ECM will still draw juice even with the truck shut off, but 3 amps IS a bunch.

 

[Billrog]

Glove compartment light ?

 

[Wagtail]

What a coincidence, my '07 Toyota HILUX (V6 4.0ltr, petrol) is doing the same thing. I reckoned that it was because I don't drive it for days on end (retired life and all that) and all of the electronics/security systems that are a constant drain over time. 2 year old battery too.

I put a 2W solar battery maintainer on it and that seemed to correct the problem... until I had a bout of overcast conditions. The battery was dead as a doornail, but re-charged fine over night.

 

[Diamondpilot]

I agree with the alternator. Also check the fuel pump. Just had a friend with a 2012 do the same thing because the fuel pump was running in the tank. Thought it might be a simple relay but ended up being the ECM and $1200.

Chris

 

[k0ua]

I agree with the alternator. Also check the fuel pump. Just had a friend with a 2012 do the same thing because the fuel pump was running in the tank. Thought it might be a simple relay but ended up being the ECM and $1200.

Chris

I wonder what the chances of stuck contacts on the fuel pump relay? The relay is controlled by the ECM, but if the contacts stuck/welded?

 

[Al Mac]

What a coincidence, my '07 Toyota HILUX (V6 4.0ltr, petrol) is doing the same thing. I reckoned that it was because I don't drive it for days on end (retired life and all that) and all of the electronics/security systems that are a constant drain over time. 2 year old battery too.

I put a 2W solar battery maintainer on it and that seemed to correct the problem... until I had a bout of overcast conditions. The battery was dead as a doornail, but re-charged fine over night.

I had the same problem with a 2001 Ford Expedition some years ago. I did everything and some other items suggested above. After many hours and weeks I was totally peeved. I ended up taking it to a shop where they tried some things (rechecking my work and extra items) a put a computer in it from the junk yard. Problem solved.

Al
That worked and the rig is still on the road (new owner).

 

[downslope]

Thanks for all the suggestions, I will keep checking things out.
If fuel pump were running, would you be able to hear it by listening near tank?

 

[k0ua]

Thanks for all the suggestions, I will keep checking things out.
If fuel pump were running, would you be able to hear it by listening near tank?

yes...

 

[Diamondpilot]

Thanks for all the suggestions, I will keep checking things out. If fuel pump were running, would you be able to hear it by listening near tank?

Yes. But some are very quite.

Chris

 

[Stimw]

I had a similar issue with my 04 Silverado about 5 years ago.
I started removing fuses and found the passenger seat fuse was drawing power.
I cycled the seat and it was OK after that and I haven't had a problem since.
I love my Chevy!!

 

[Bird]

I remember from years ago when a fellow who worked for me bought a new Chevrolet sedan to drive to work. He soon found out that the battery would be too dead to start the car on Monday mornings if he hadn't used it over the weekend. But no problem if he didn't leave it parked for more than one day. Since it was new and under warranty, he took it back to the dealer multiple times before they found that low current draw was a problem with the cigarette lighter.

 

[Blaneypark]

Take the battery to the local auto store and have them do test on it. They don't make them like they used to.

 

[crashz]

Does the truck plow snow? My fathers 2011 would be dead after a few days because he would leave the plow controller on.

Do you ever use a power inverter? My 2004 was cooked due to the use of one. I replaced the alternator and chased electrical gremlins from their until I traded it.

How clean are the trailer connections? I've heard of power loss when corrosion on the truck side plug is severe. The same goes for clean battery tops, but 3 amps is way more than I would expect de to dirt or corrosion.

 

[crashz]

Does the truck plow snow? My fathers 2011 would be dead after a few days because he would leave the plow controller on.

Do you ever use a power inverter? My 2004 was cooked due to the use of one. I replaced the alternator and chased electrical gremlins from their until I traded it.

How clean are the trailer connections? I've heard of power loss when corrosion on the truck side plug is severe. The same goes for clean battery tops, but 3 amps is way more than I would expect de to dirt or corrosion.

 

[tcartwri]

On my neighbors it was the power distribution block itself. ( the thing that all the fuses plug into ) Burned and arced circuits inside the block.

 

[downslope]

Re: Battery Drain 2008 Chev--Solved??

OK, problem is located but not fixed. Appears the malfunction is with the Sirius/XM radio and/or OnStar system. When I pulled the radio fuse current dropped much lower, maybe around 1 amp or less. Hard for me to tell exactly as I only have an analog ammeter. I also pulled the DIC fuse which supposedly also powers the OnStar. I was hoping for a simple problem like alternator, but apparently no luck.

These things are very hard to pinpoint without the right equipment and/or a lot of time. The diffferent modules (PCMs, BCMs, etc) continue to draw power even after you turn the key off. And then they will restart/reset after you disconnect the battery cable when you put the ammeter into the circuit. You have to get the ammeter in before you break the circuit, ie. you have to parallel the ammeter with a switch so that you never lose power to the modules. Some of the modules can require several hours to power down completely and go to "sleep". And then, even after they power down they can start up again, either by design or due to malfunction. Like OnStar, which will try to "call home" with your diagnostic report. This is all way too complex. Or the radio is designed to continue to play after you turn the key off until you open the door or a certain amount of time passes.
If you have the Verizon calling option with the OnStar it has to switch the speakers to the phone unit and silence the radio. It may be just a coincidence, but my battery trouble started right after I let the OnStar subscription lapse a month or so ago; who knows?

So now I'm completely frustrated and annoyed. I'm paying for a sat radio subscription but I can't leave the radio fuse in overnight. I was considering starting the OnStar up again, but now I'm thinking why bother.

Sorry this has been so long-winded but I feel I spent a lot of time on this and still no real solution.

I found and old TSB from back in June 2009 and they have you performing what seems like hours of testing with DVM and osciliscopes and then either reprograming the ECM or replacing the XM module. And this is only for the radio, similar things can happen with power memory seats, dual zone HVAC, fuel pumps, lift gates, etc, etc. I'll keep looking for more up-to-date repair documents.

How is the average guy supposed to fix something like this at reasonable cost? Have these systems gotten more reliable in the past 8-10 years, I hope so? Maybe those were lean times for GM designers back then?

 

[skipmarcy]

Re: Battery Drain 2008 Chev--Solved??

I've been having to diagnose these very same issues on a daily basis for over 30 years now - people don't really realize the true cost of all these bells n' whistles. People don't understand the hours it takes to do a diagnostic on some of this crap, and the cost of the equipment to do it. We had an early 2000's Cadillac that took us 3 days to pinpoint the culprit causing the drain - ended-up being the multi CD changer in the trunk . We simply had to unplug it to eliminate the problem. It wouldn't "go to sleep" and it kept the BCM from going to sleep as well. The repair cost virtually nothing, the time to find it was extremely costly. Lots of problems with factory security systems nowadays too - the ones that are about 10+ years old are starting to go south on a frequent basis. These hack mechanics trying to install aftermarket equipment tap into critical wiring under the dash or hood and cause really weird problems too.

Just read in a trade magazine today where there have been cases where cellphone use (RFI) have set air bag fault codes, and some of the chargers that you plug into the cig lighter have oscillators that cause RFI (radio frequency interference) and cause no-starts in some vehicles. And they want to have these self-driving cars on the road here soon ...