The problem seem to be one that the dealer computer does'nt see.
It will be fine for three weeks then it starts draining the battery over night.
the dealer put in a new battery was fine for three weeks now will go dead over night sometimes. to me it sounds like a main realy is not shutting off power to the system when the car is shut down. I do notice with the key out and (and car is off) the raido will still work, the nav dvd system never turns off(the red light is always on), and if I turn the turn single on it light but not blink. The car has 113,000 miles, may be the ignition switch is wore out?
any thought will helpfull.

 

You may think I'm out of my mind with this suggestion but check the jump connection under the hood for tightness. It's the positive + connection. If that is loose, you will have the same issues. Happened to me with my R53.

 

Have the dealer check wiring and connections for a slow drain or short.

If you have other sources for power drain like aftermarket electronics- audio, video or alarm then those are potential problems.

Your new battery should not drain after three weeks.

Check charging system- belts and alternator.

The stock radio is supposed to work with no key in the ignition. Just turn it off.

 

+1 I had the loose connection at the jump stud under the hood and the electrical system wasn't charging properly.

 

I checked the jumper terminals this moring, clean and tight, the dealer just put a new battery in 4 weeks ago. they removed my year old third party battery and put a OEM battery in even though it started fine, they said they had to do this before they could hook the computer to it. at a cost of $350.00 just to check the system.
I will be looking for the schematic and do the chase down myself..wont take her to the dealer again. I always enjoy a challange.
thanks all.

 

jackrs - did you ever solve your problem with the battery? I have a similar problem and every time I take it to the dealer they can't find anything wrong. But intermittantly, it will not start - battery totally dead. I've replaced the battery and still have problems. Seems to be worse when it rains?? Anyway - just thought you might have some insight.

thanks!

glen

 

does'nt seam to be rain and yes I still have the problem, for the last two months it's been fine no problem, but i'm lookng forward to the day (anyday now) that it does it again. I think it may be my nav system not shutting down after the car is turned off....On a trip I noticed the nav screwing up
went into a gas station for 10 minutes when I came back the nav was still up on screen...key was with me. when this problem first started it was very cold had to jump it and ever sence my nav system has been intermittent.
jack

 

Thanks for the reply. I noticed my problem a month or so after the dealer installed an ipod connection for the radio. Thought it was an old battery so I changed it. Everything fine for a while, then it started again. I had noticed that the driver's side window would intermittently not work. Would not roll down for several weeks, then it would mysteriously start working. Also, the problem with the battery cropped up again. Dealer replaced the window motor and said the battery problem was because it was an after-market battery - I think that's not correct. Anyway, it works fine for a few weeks then I go out in the AM and it's totally dead. Very frustrating because every time I take it to the dealer to check it out, it's working fine!! I'd really like to get this fixed - but the dealer just wants to sell me a new battery for $400.00 installed!! I took the car back to Sears where I bought the battery and they check the battery and charging systems and said everything is working fine. In spite of what the dealer says, my contention is that something is not turning off and is draining the battery. But what?? I don't have a nav system in the car. Thanks for the reply!

Glen