I have the meter set to 20m and show an amp draw of .24 on the digital readout, while not in sleep mode. Then after several minutes, it drops to .09, so I assume this is sleep mode.

First off, I don't want to assume .09 mean .09 ma, so I would like to first verify this. Reason being, I was under the impression from reading all the stuff on battery drain, that these cars should be around 20ma.
The .24 reading would be 24 ma correct?
So why am I reading .09 in sleep mode? I read that some cars go as low as 15 ma, but .09???

2001 all stock.

 

Edit: My bad. I was reading a couple articles on anti-freeze and measuring voltage flow and then jumped over to this thread.

I don't recall the exact number range for current flow on our C5s right offhand, but .24 is the same as 240 ma and .09 is 90 ma. Most newer DVOMs are "auto-ranging" and set the proper scale (within the maximum limits of the unit itself of course) automatically.

 

Can you post a picture of your meter? You disconnected the negative battery terminal and put the meter in series, right? You should be getting around .020 amps (20milliamps) in the sleep mode. I'm not sure what range you are on with the meter and seeing those numbers. Maybe a picture would help.

 

Went out several hours later, and the reading was .02 as seen in the photo. This is 20 ma correct? Earlier when I checked it, it was .09. The .09 was maybe an hour or so after I last disturbed the car by opening a door. That should be plenty of time to go into sleep huh?

The 01 vert. is new to me as of 3 days ago. I have not driven her yet. PO was disconnecting the battery after each ride, due to a dead battery after around 3 to 4 days. He claims is was doing this 6 years ago when he bought it, and he never addressed the issue. Records show he put in a new battery 6 years ago, and he claims it still did the drain afterwards.
Since this battery is now six years old, I suppose my first course of action should be to put in a fairly new Optima red top that I have as a spare. I can leave it hooked up, and see how it goes. The .02 amp draw I'm seeing (if that is what it is), should not drain the battery. What I'm wondering, is if something is causing the car to come out of sleep mode intermittently.

Any thoughts along those lines? Seems to me I'm going to have to first verify the battery drain is still happening. Surely it didn't just stop because it likes Texas better than Florida? LOL

 

What I recommend you do is charge the battery and take a reading of the voltage at the battery when done charging. Just let the car sit and don't do anything except lifting the hood and measure the voltage at the battery about every 12 hours and record your readings. This will tell us if you have an excessive drain.

If you start with about 12.7 volts then it should take about 3 weeks before you are down to 12 or less if you have no abnormal drain.

I have seen where BCMs decide to wake up and start actuating circuits and drain the battery overnight.

 

Funny! That is exactly what I'm doing. I downloaded a chart, and took my first reading about an hour ago. The battery was at 92% when I took the reading. I figure it will tell me the same story.

 

Great, even though I have no idea what you mean by starting a test and you start at 92%.

 

With a good battery that has the correct Reserve Capacity, you be able to start your car well into 30-35 days of setting idle without any issues. Been there done that.

If your car suddenly kills a battery in a short period of time, it could be because something that normally shuts down or turns off at key OFF,, DIDN'T!

Some things that I have see remain on are:

Seat adjustment motors
Seat Bolster air pump
Interior lighting
Hood light
One of 25 different relay that may weld themselves ON

Like you mentioned, some early cars had passive/active FOBs that could cause the car to lock and unlock if the FOB was close and moved. That would cause the BCM to come out of sleep mode.


20-25 milliamps (.02 amps) is the designed range.

Bill

 

I did a voltage test on the battery, and with a voltage reading of 12.57 IIRC, that would indicated a charge of approx. 92%. I saw no reason to charge the battery up to 100%. So I started my test at 92%.

After 10 hours, the voltage has not dropped. I'd say there is no battery drain. I called the PO just to pick his brain about this, and as it turns out, he was letting the car sit for several months at a time, and he took this to be a problem. His remedy was to use a battery disconnect.

Now I will start another thread on all my other "issues", real or imagined

 

On your picture the meter reading 19.99 would be 19.99mA or 0.01999A. Your reading of 0.02 in the picture translates to 0.00002A.

Considering the car should read somewhere around 0.02A, your meter is low by a factor of 1000 which is impossible on a properly functioning C5.

I wouldn't be surprised if you've blown the fuse in the meter. If the fuse is good, then you've got the leads in the wrong spot or the meter is defective. Also possible that the leads are connected to the terminal and battery post properly.