Had this issue for three years now and have through three batteries already. I checked with Autozone to have my alternator checked and they said it was good. I forgot about this issue until today when I turned the engine off but left the car on the on position. Sat for 30 minutes than tried to start the engine; nothing, completely dead. At first it stuttered than just starting clicking (probably the alternator).


I do have the police interceptor model with the 3.9L v6 and was wondering if the wires that were left over from the previous police department could be draining my battery? These wires are between the passenger and driver seat and run underneath the black rubber carpets most police have. There'* also a bunch of wiring in front of the passenger side and they connect to the electrical box at the bottom of the passenger seat. How can I remove these wires?

I'm not sure which wires you can and can't disconnect, but the most common way to track down a parasitic draw is to pull fuses. Pull 3 or 4 fuses at a time, see if the parasitic draw is gone or not, and if not replace the fuses and pull 3 or 4 more. Once you find the 3 or 4 that affect the draw, pull them one at a time.

Well, I just used a multimeter to check and see if there was a draw using the highest settings and going down from there. I saw basically 0 on all the readings.

When you install an ampmeter between the neg cable and the neg bat terminal, you should get an initial high reading, because you have awakened the modules....it can take 10 minutes or more for the modules to go to sleep....as they go to sleep, the amps should drop.....your final reading should be around 25 ma or less(0.025 Amps)....

Well, I put the one end of the multimeter on the negative battery, and negative terminal. I see a reading of around 2.5-3.0 amps while the car is off. After 20-30 seconds though, it drops back to zero. I don't know if there'* a draw or a false positive and it'* confusing. I checked the battery and it had a lot of corrosion at first when it died (but only on the negative side) I cleaned it, charged it and it'* been fine for the bast few days. This has happened on four or five other occasions before and I've changed the batteries 3 times so far. I just don't know what to do.

I can find some info to help you check for the draw, but it sounds like you already have an idea of what you are doing.
On second thought I'll post links that may help others in the future.

How to Find a Parasitic Battery Drain - 9 Easy Steps

Or a semi ok video


It should take more than 30 seconds for the car to go into "sleep mode" though, odd that it happens so fast.


If you cannot find the issue and fix it, then until you do I can tell you one way to get by until you figure it out.

One of these
Be sure to get the Ring Terminal Harness.

As long as you have somewhere to plug in an extension cord you should be able to use this method to get by, it is what I have had to do for a while.
I leave the battery tender under the hood, just be sure to let the motor cool a little before you put it back under there after driving it.
NOTE: I have had mine since February 1, 2012, and it still keeps the batter charged even though I still have a draw, eventually I'll get around to chasing it down, I just have yet to have time to, and since I have the maintainer I have kind of set doing it aside.

Good video William.....

In addition to what he said, one thing I do, is use the GM special tool to do the draw test.......basically, it is a circuit interrupter......it attaches between the negative terminal and the negative cable, and has a switch to open/close the circuit......and has attachments for your meter ends....

As the guy in the video explained, some luxury cars can take up to 10-20-30 minutes for all modules to go to sleep(found that out the hard way with a Park Avenue)......if you just stick your meter in there, some meters go to sleep, before the modules do......you turn your meter back on, and you are basically waking the modules back up....nobody has this tool.....so you make one.......piece of wire with two alligator clips.....disconnect the negative cable, from the battery, install a bolt into the neg terminal(makes it easy to attach the alligator clip), attach the terminal first, and the cable second, while holding the cable as far away from the battery as possible(may have a small spark....don't want sparks near a battery...hydrogen gas)......this allows current to flow......turn on your meter and using alligator clips on you meter leads, attach you meter leads in parallel with the jumper wire......your meter will read close to zero, because all the current is "shorting" through the jumper.......now remove the jumper lead from the cable.....all current now flows through the meter......like I said before, if this was a PA, you would get an initial reading of 3-5 amps....over the course of 20 minutes it will drop in stages, eventually dropping to 25-30 MILLIAMPS........problem is, my meter will shut off automatically before 20 minutes......so, I just reattach the jumper after taking a meter reading(remember, this will make the meter go to zero again)......check it in 5 minutes by removing the jumper(cable end), and looking at the reading.......reattach jumper....now if I come back and my meter is off, I disconnect one end of the meter, turn it to off and then back to my current setting, and reattach the meter end...since nothing is disturbed(the jumper is still in place) I am still in business.......then usually after 20 minutes, with that meter on, I remove the jumper end and get the reading through the meter and it should be in the 25-30 amp range...

One thing not mentioned in this video, if you pull all the fuses from all the fuse boxes(remember, there can be more than one), and you are still getting an excessive reading, then disconnect your alternator......could have a bad alternator....

Also, as explained in the video, you could have spikes in the reading, as something turns on....he explained key module doing this.....something like OnStar can do the same thing, as this module will occasionally wake up and do a com check.....so the main thing is, read the meter, and if high, recheck a few minutes later, to see if it drops....you could be chasing your tail for something that is normal.....

You mentioned onStar and my car (since it'* a police version) isn't equipped with it yet when I checked the passenger door fuse box, I see an onStar fuse. Can I just remove this fuse? I can't check the parasitic draw since the multimeter drops off after 20 seconds when I hook-up to the negative battery. I don't know what else I can do.

UPDATE:

Here'* What I noticed today, impala'* have a headlight system on the left of the driver seat. Which has automatic, off, and some other features. I noticed when it'* on automatic and I turn the key to the on position the headlights turn on (automatic of course) and than when I try to crank the engine, slips and stutters but won't start. Now, when I set the automatic lights to off, engine starts normally. What could this mean?

Any issues with the security light coming on and staying on?
How is the battery as far as charge goes?
With the car not running, check it with the multimeter and see what it registers.