Help Battery keeps going dead!!!

EDG08 · #1 12-09-2009, 08:21 PM

So today in MN we hit a wopping high of 5 degrees with about 6 inches of snow. By the way i put some winter tires on the 4.6is and it handels great!! (20x8.5 square setup) So my question is it started just fine this morning, and then at noon the battery was dead. I had a friend jump it and worked just fine. I went out again at about 3 and started just fine and then when I was ready to leave at 5 it was dead again. The one thing I notice is that my Park, Neutral, Drive, Reverse lights are not shutting off. I left it sit for about 15 minutes and when I went back they were still on (the ones by the shifter) everything else was off. So Im guessing that is what is causeing the issues, so how do I get those things off?
Thanks guys

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Weasel · #2 12-09-2009, 08:45 PM

Yeah, I'd say something isn't shutting down. It usually takes a while with an amp clamp to track down the culprit, but you can always start by checking the usual suspects. First see if the fan stays on when the key is off, as the FSR does that kinda thing when it goes out and is one of the biggest draws you could see. Otherwise you could try pulling fuses of suspect systems while reading the amperage. If you don't have access to a way to read amperage down to the miliamp range (without putting a meter in line as it will blow the fuse in a meter, which is why inductive amp clamps are the way to go) you may need to pay the dealer (or a shop with such experience on BMWs) a couple hours to diagnose it/track it down.

EDG08 · #3 12-09-2009, 09:22 PM

Thanks Weasel,
The fan does not stay on when the key is out. Does this mean it is not the FSR? FSR was the first thing I thought of but the issue is not the main fan system. When I shut off the truck and sit in it for a little while the P,D,N,R stays on and I can here a faint noise by the glove compartment (maybe it my imagination knowing that is were the FSR is located) but it almost sounds like a small fan of some sort. I guess I could take it in to the dealership but if I could diagnose it as the FSR I could just get one of those and change it myself (i think there are directions on here somewere to do it).
That way I would save a couple hundred bucks but if it is a fuse thing then I will have to take it in. Can I just start pulling fuses and when the PDNR goes off replace that fuse or is it much more difficult than that.
Thanks again for the help Weasel You have helped me out a couple of time now!!

EDG08 · #4 12-09-2009, 09:34 PM

New development, I just went out to check if the lights were off and the were! so I start her up and idle for a little bit and then shut her down, get out and lock the doors and now the Nav screen stayed on (black screen). So I let it sit for a little bit and never shut off so I get in and turn the key and the nav pops on, then take the key out and the nav is off but the P,D,N,R stays on again. Unreal, fricken cold MN weather! So I dont really want to take it to the dealer and have them check into it and then everything shuts down properly and im out 2 hondo. Cuase I know my luck the time i bring it in it will work just fine. Man, I dont know what to do, guess I can just buy a battery jumper and stick it in the back! thats great I have a 70K beemer and I carry a battery jumper in the back as if I have a 1980 olds!

Weasel · #5 12-09-2009, 10:31 PM

How old is your battery? I ask because cold weather plays hell on batteries that are getting old. If the battery is a couple years old I'd suggest a high level charger (not trickle) charging overnight to get it up to a full charge and in better condition than before. I say high level charge because holding a battery at about 14.5 to 15 volts at a high amperage (20-40 amps) will actually get some sulphation off of the plates and bring the battery to better health and give it the ability to hold more charge than before. (assuming there is some sulphation in there which is very common with older batteries)

If you don't have access to a regular charger a trickle charger is better than nothing, but you need to get a full charge on her... not just a shallow charge from jumpstarting then a short drive.

recklessspyder · #6 12-09-2009, 11:25 PM

Wow, same thing just happened to the wife today. Now, I've had a recent history with the battery dying. It happened a few weeks back....got it charged back up and it's been fine since, until today. Of course, it's after a big snow storm and she was stuck at work. I have a new battery (replaced in summer). I have a list of things for the dealer to look at as suspects.

1. Just put my winter tires on.
2. Driver mirror starts adjusting like crazy when I unlock the doors
3. Fan inside seems to be always buzzing when car is not on (dealer tech told me that it is normal)
4. Last time battery died, bluetooth also went out. I went and checked the fuses and re-seated them and checked wires at module and bluetooth started working again (or reset itself since fuses were pulled)
5. There are a lot of post on battery dying...but no one ever seems to have it solved (or posts it)
6. I have a multimeter and somewhat knowledgable with using it (at least for checking battery and alternator voltage). I could do some self diagnosis, I suppose...but it's cold now and don't want to.

EDG08 · #7 12-10-2009, 12:02 AM

Dont know how old the battery is being i just got it this summer. I guess that is probbly the best thing to start with. Any suggestions on a good battery for a 4.6is that is driven in MN (it gets COLD here in the winter!)

Weasel · #8 12-10-2009, 03:00 AM

If the fan stays on with the key off, you likely need a FSR, which can cause an erratic/bad battery drain when it goes bad. You can find writeups on it in the forum and pull it out to check, when it goes bad I can tell by looking at it.

Quote:

Originally Posted by recklessspyder

Wow, same thing just happened to the wife today. Now, I've had a recent history with the battery dying. It happened a few weeks back....got it charged back up and it's been fine since, until today. Of course, it's after a big snow storm and she was stuck at work. I have a new battery (replaced in summer). I have a list of things for the dealer to look at as suspects.

1. Just put my winter tires on.
2. Driver mirror starts adjusting like crazy when I unlock the doors
3. Fan inside seems to be always buzzing when car is not on (dealer tech told me that it is normal)
4. Last time battery died, bluetooth also went out. I went and checked the fuses and re-seated them and checked wires at module and bluetooth started working again (or reset itself since fuses were pulled)
5. There are a lot of post on battery dying...but no one ever seems to have it solved (or posts it)
6. I have a multimeter and somewhat knowledgable with using it (at least for checking battery and alternator voltage). I could do some self diagnosis, I suppose...but it's cold now and don't want to.

recklessspyder · #9 12-11-2009, 12:36 PM

An update: I went to jump the car last night and couldn't get it do anything but click. It was 5 degrees so I didn't think it was going to be easy....but anyway. Wife and I tried for a good 15 min and i decided to open up the back end lift gate. I had originally thought this was going to be the issue for the battery drain as it terminally killed by battery in summer by not be fully closed/locked.

So opened up and closed the lift gate....went to start it up and it fired right away. I'm assuming the the motor was still trying to activate while it was connected to the other car. Opening and closing the lift gate shut off the motor, giving the car enough juice to start.

I drove it home and left it in the garage to run for awhile. Shut it down and it fired back up. I'll be going out there again shortly to take it for a longer drive to charge....so we'll see if the lift gate was again my nemesis.

I'm still probably going to replace the FSR since I bought the damn thing.

Thoughts?

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