Battery Drain - 2002 Chevy Astro

astro
chevrolet

#1

Hi,
I’ve recently been having battery drain issues with my 2002 Chevy Astro. After taking it to a local garage I was informed that nothing was wrong with it other than it needing a new battery. They put a new battery in and within two weeks of the van not being used the battery was dead. I did a bit of research online and learned that something may be drawing power while the van is off, and that I could do a fuse test with a multimeter. After performing this test I narrowed down the drain to being related to the following fuse:

19 Instrument Panel Radio: ATC
(Main Feed), 2000 Series (Standby)

The only things that seem to be on this circuit are the radio, cd player and some elements of the instrument panel (e.g. odomoeter). I’d like to fix this problem but I’m sort of stuck as to what I should start testing from here. Today I disconnected the radio and cd player and tried performing the multimeter test again, with the fuse back in place. It appeared that there was still excess power being used with the vehicle off.

Any advice on how I can narrow this down further?

Thanks…


#2

Fuse 19, 10 amp supplies power to the radio only. However out of the radio is a circuit to the interior lighting system which includes the Body Control Module. Did you wait at least an hour before testing for the current draw? Sometimes it takes that long of time before all the modules go to sleep in the vehicle.

Tester


#3

Hmm, I don’t think I waited an hour before performing the test. Looks like I’ll have to try it again. Thanks for the info.


#4

Another question…since the radio is technically the only thing being powered by fuse 19, would replacing the radio be a possible solution to the problem? Or could the issue be in the wiring that leads to/from the radio?

Sorry if those are stupid questions, this is the first time I’ve ever tried diagnosing an issue with a vehicle by myself. So I’m learning as I go along.


#5

I guess the first question is: how much (in amps, milli-amps, etc) is the “key-out-and-everything-off” current draw in that circuit? As mentioned above, you need to measure this right after turning everything off, and about an hour later.

Is everything that uses electricity original to this car? There’s no extras installed, like alarm systems or a big woofer stereo speakers, right?

I can’t imagine an originally installed radio drawing much more than 1 amp even it was playing Grateful Dead music. With no sound coming from the radio, even if it is on, it shouldn’t draw more than 50 mA or so. That shouldn’t drain the battery. Even a 1 amp draw wouldn’t completely drain a good fully charged battery in a day. There must be something else going on. Are you certain the alternator is fully charging your battery?

One thing you could try is to pull that fuse. As long as the other functions on the circuit aren’t critical to driving the car safely, try it without the fuse. You can live without the radio until you get this diagnosed and fixed.


#6

If I recall correctly, it was about .13-.14 milliamps with everything off (doors closed, no key in ignition, etc…). On a couple other sites I read that that was too much draw and that it should be closer to .07 or less. After pulling that fuse, it drops down to about .06-.07.

It’s a used vehicle, so I can’t be 100% certain everything electrical is original, but I’d venture to say that it most likely is. Definitely no stereo components or alarm systems installed.

It wasn’t totally draining it after a day. It seems like it took a week or two to drain it down. I’m not sure about the alternator. The garage I took it to assured me that it was fine. I don’t know enough to be able to test it myself.

I’ve been leaving the fuse pulled for now…and that’s a decent solution for the time being. Unfortunately, I was just getting ready to sell the vehicle and that’s when this problem seemed to pop up. It makes it a bit less marketable when I tell people it has an electrical issue.


#7

Did the digital multimeter DMM perhaps read 0.13 amps? Or did it indeed read .13 milliamps.
.13 milliamps is so small that only a very expensive DMM would be capable of displaying it.
On the other hand, 0.13 amps is actually 130 milliamps, which wold be too high. That is likely not high enough to kill your battery overnight, but it will kill it in a few days.
If your DMM reads 0.6 amps (60 milliamps), that would be acceptable, but not great.
How high is the draw with the fuse installed, after waiting some time for everything to go to sleep?


#8

Uhmm, 0.6 amps is more than 4 times greater than 0.13 amps.


#9

It seems like there may be some ambiguity how much current the off-state is drawing. 0.13 amps (130 mA) is higher than I’d expect to see and could possibly drain the battery over the course of a week (with the car not being used). Even sooner in cold weather. 0.13 mA wouldn’t be a problem not matter the temperature. There’s a factor of 1000 difference between the two. We’d have to know which it is to offer further advice.


#10

Yeah, oldtimer 11, you’re right. My math was flawed. 0.6 amps would be 600 milliamps. An unacceptable draw.
So here’s some more questions, dmf . . . Does your DMM display current draw in amps or milliamps? Is the DMM autoranging?
Do the current draw test again, with fuse 19 installed, and then again with fuse 19 removed, please, and let us know exactly what the DMM displays. For example 0.6A or 0.06A or 0.006A or 60ma or 600ma, etc.

Thanks


#11

how long is the van seating between been driving. my 2000 300M can’t seat more then a few days with out been driving. it might pay to buy a "Battery Tender"and plug the van in when its going to seat for more then a few days. good luck with your sherch for the problem.


#12

Normal current draw while the vehicle is parked and things have gone into the ‘sleep mode’ should be less than 25 milliamps (.025 A), for most vehicles anyways. A 130 milliamp or 70 milliamp draw can cause the trouble described. I don’t think there is a sleep mode for the radio itself and if so the current draw for it seems too high to me for whatever reason. Once the radio is disconnected perhaps the current drain will go down further more to a normal level if things weren’t going into the sleep mode when the current was checked. The delay for the sleep mode varies between vehicles. The ones I have tested in the past took less than a minute to do but I have heard some can take at least a half an hour for it to happen.


#13

Did replacing the radio work, we pulled the fuse and it stopped the battery drain, but the day it started was also the day the stereo quit working. It’s been -10 to -20 here in Alaska so battery goes dead fast. I’m really curious if replacing the stereo is the easiest fix.