loyalkipper

Having some issues with my battery and a parasitic drain. Its been an ongoing issue for last week and a half after replacing a 6 year old battery killed by leaving glovebox open over night.


My car: 2000 Audi A4 B5 Quattro 1.8T, bone stock
New battery from Advance Auto (manufactured 5/12)

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Details

Original battery was about 6 years old when it died, on a hot day 100 deg, the car would not start. Most likely cause was that I left my glovebox open all night.

Got a new battery, and it started fine. The voltmeter on the dash indicated it was charging fine. The car was fine all day with a couple stops for errands etc.

The next morning it would not start, total elapsed time since turning it off was about 12 hours. Got jumped started and again the car ran fine. I took it to Mr. Tire to get diagnosed, the guys said to take back to Advance Auto (where I got the battery) to get them to test it in case they sold me a dud, it passed fine.

Took it back to Mr. Tire, they said if the battery is fine, the starter is fine, and the alternator is charging, there was not much to do. So I went on my way.

I decided to pick up a battery booster/jump back just in case. For the next couple days, I had no issues with starting even after letting the car sit for 12 hours until recently.

I had one case when the car would not start, the jump pack (a Black/Decker 350amp CCA) was able to get it started, after that, the car ran fine for the remainder of the day.

Today everything went wrong. It started fine after sitting for 8 hours (at work) but within 100yards all the power cut out, dash was on but no steering or brakes. I had to pullover in mid-traffic. The booster pack was unable to jump it, so the battery must've been severely drained so much so the alternator was not able to provide enough charge in that short time to sustain the engine. Eventually a friend came who used his car to jump me.

I was able to make it Mr. Tire who said that I should take it Advance Auto to get a full test ie. battery, load test, drain test. The car/battery passed everything but the drain test meaning my starter, alternator and battery were fine. The drain test revealed a 2.72amp draw within 30 seconds of turning off the engine. What could cause this?


I am currently running a quick fix, picked up a manual battery disconnect from advance auto and installed it. A pain to toggle every time but better than a jump. Before I burn money trying to pay a pro to track down the parasitic draw, does anyone have any tips on where to look. I plan to get a multimeter to do some probing soon.

AudiMick

Normal draw is under 50mA with the key out. So you have something drawing about 30 watts.

30 watts is not much so it's nothing heavy duty like, headlights , a cooling or blower fan.

Pull fuses on the panel until the draw goes away, check for things like brake lights and after-run coolant pump. Interior lights etc.

If you have an aftermarket stereo make sure that is turning off and external amp/ sub is powering down.

There is a device that plugs into the fuse holders in the panel that you can hook a ammeter up to.

turbo510

All good advice from Audimick- and easier if you have a 12V test bulb to put in series with the + battery cable. Pull fuses, reinstall untill you find the circuit that turns off the light. Let us know what you find.

But that part where you went 100 yards, then the engine quit and wouldn't restart; that isn't what a depleted battery does. Something else is wrong.

loyalkipper

Thanks for the tips.

From what I've come across while searching is a possible dead interior bulb (trunk light or glovebox) or something called the Comfort Control System. Someone suggested touching the bulb to see if it is warm, esy to do with glovebox, as for trunk, a little trickier as I may get locked in. Another thing I've heard has to do with the motion sensor feature of the security system ie. 2 levels of security, single (locks lock) or double lock (activates interior motion sensor)


The guy at Advance Auto said that 2.72amps is quite a significant drain. Is it possible that a faulty ground or wire is causing it?

It'd be great if it was simple fuse issue and not something that involves gutting the interior to trace it or for that fact having to pay someone to trace it

loyalkipper

That aspect was most terrifying. I was making a turn out of a parking lot when the steering locked up, I almost drifted into oncoming traffic, plus the brakes didn't work.

My initial thought was that the car was able to start using the last dregs of power in the battery, but the alternator wasn't able to recharge enough in that amount of time to keep the engine running.

Another thing I should mention, the car's ABS system has died for quite some time (ABS + flashing BRAKE light). I'm not too concerned with this as a cause because it's been like this for a long time. BUT, the check engine light is on, maybe it's related or not, it has comes on intermittently recently and seems to stay illuminated when driving.

mtroxel

It's hard to connect these dots. I think you have two problems. You would have brakes with no engine and no electic. You'd loose the power assist for the brakes, but then it comes down to hydraulics and you'd still have brakes. Same with steering, unless you're talking about the steering column lock kicking in.

When you track down the parasitic draw, keep in mind that our cars will pull about 2 amps for....I don't remmber. I think it's a little over a minute...before everything shuts down, then you're down to about .04 amps as I recall.

But if you're losing your brakes, that's hard to connect to a loss of electic.

loyalkipper

Perhaps I misspoke, I did in fact retain braking and steering, I just lost power assistance. The gauge cluster was still lit up and reading too.

When we did the drain test, we let the car sit powered off for maybe 30-40 seconds from which we got the 2.72amp drain, did we jump to conclusion? When we turned it off, it actually climbed to that value. At initial power down it was 0.6amp and then climbed to 2+amp after 30-40seconds and kind of stabilized at that number.

mtroxel

Alright loyalkipper, who loves you more than I? It took a trip to Radio Shack and some time under a hot hood in 95 degree weather. But here it is.

Set up your multi meter so it will take 10 amps. Disconnect the negative terminal, clip one lead to the - on the battery, the other to the - cable. Make sure the blower on the AC is off or you'll blow the 10 amp fuse (hence the trip to Radio Shack). Then turn the key on to power up (don't start it though...you'll go back to Radio Shack) for just a couple seconds, then off. Close the doors and trunk. You should pull about 1.4 amps for 3 minutes. Then the after run coolant pump turns off and you're down to .04 amps and it should stay there. If not, remove half the fuses, then do it all again. If it settles down to normal, it was something connected to the fuses you removed. Start adding them back till you get to the circut that's killing you. Otherwise, pull the another half of the remaining fuses till you get rid of the problem, then work back to find the one.

loyalkipper

Thanks the instructions. I'll try and give it a go after work tomorrow. Are we fairly confident at this point that the drain is attributed to a fuse/bulb issue rather than some obscure wire buried within the car?

I'm assuming this approach (using a multimeter) is better than the 12volt bulb approach?

Let's just say, if the cause was in fact a bulb that was not turning off, simply removing the bulb should fix it, correct?

Any risk with removing multiple fuses at a time? My only concern is not being able to put them back in the right order/position. I'm guessing radio shack does not carry automotive fuses, so my best for replacements would be advance auto (are the fuses a special-order ordeal or OTC?)

Not sure if this is relevant info but my car is hovering at around 93K miles on the odometer, so not really used too much.

Thanks again

mtroxel

Not necessarily. It might be lit because of a dead short that's lighting it up.

Nope. I've done this. Just keep track of where they go.

Radio Shack has 'em. So does every auto parts store.