We have a new battery and a new alternator. The car runs very well, but once a week or more the car is totally dead, no dash lights just nothing. We do not activate the alarm with anticipation of this problem...We have taken to the mechanic and he claims that all is well.
What to do?
I have a 2000 528 i and my battery kept going dead.. My factory amplifier for my radio went bad and that was draining my battery... If you charge the battery, then let it sit for a hour or two,(obviously with the car off) then feel the amp and see if it is warm.. That is how i found my problem.. Hope this helps... good luck.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
It sounds like an alternator related issue. Once the battery drops below 12 volts it will do lots of silly things with gauges and thats why when you change it all works fine. Check that with engine running with a volt meter you have 13.8 to 14.2 volts across the battery, if not you may have an alternator issue
I would make sure that the alternator is charging. It might be that you need a new battery, but without knowing if the car is charging you would eventually have the same issue. Most any parts store can charge and test your battery and tell you if it needs replaced or not, they can also test your alternator to see if it is good. A simple test would be to get a voltmeter or multimeter set for VDC and check between your positive and negative battery terminals with the car running and see if you have more than 12V. If the alternator is charging you should have around 14V.
Lead acid batteries don't like being discharged flat, and it could now be damaged and unable to hold a charge. It does sound as though the voltage regulator part of the alternator is allowing discharge to ground when it should not. You would seem to have a good warranty claim on the battery given they did check the alternator and pronounce it OK.
It sounds like that not only is the battery totally dead ,due to a high very internal resistance, but that the alternator has very low output. While car is idling in neutral, the alternator has just enough output to supply the ignition circuits but once in gear and the idle speed drops there is insufficient voltage to run engine so it stalls, It is the same when the lights are turned on as the alternator cannot supply enough to run lights so engine dies without enough drive for the ignition circuits. Try another battery or install a new one. Also have the alternator output checked as it could be the cause of the battery dying in the first place because it has not been maintaining charge as you drive. The alternator problem would be caused by either worn brushes and / or a faulty electonic voltage regulator which is mounted inside the alternator with the brushes.
Welcome to the world of BMW's. return the car to the seller. you got a bad one. You got an electrical short draining the battery. Bring a blank check and sign it over to the dealer. They're going to have to run through the entire electrical system to find the short. That work alone is worth more than the a used up 2001 325i.