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1994 BMW 325i

Question: Alternator and battery problems

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Carl3, Lithonia, GA, June 01, 2010, 10:09

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My car has no trouble starting, however when I take the positive battery cable off the car automatically turns off. I also just put in a new alternator. Does anyone know what may be causing this problem?

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• Answer #1

  dandd June 01, 2010, 15:36
  

   Master

  I would NOT do this. Your BMW has very sophisticated electronics and when you take off the B+ cable, you are full fielding your alternator, which is a dangerous thing to do for the computers on your BMW. The voltage regulator is no longer in the Alternator on your car, it is controlled by the Power Train Computer, so when it sees a lack of continuity with the B+ cable, it shuts down as a safety measure. This car is NOT like an older car, where you can take off the B+ cable after the car is running and the car will still run. Please don't keep doing this.
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  simona, July 23, 2010, 20:49
  

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  I have the same problem I changed 2 alternator in 3 weeks , and today my car died on my driveway. If you find what was the problem with your car, please let me know, i am desperate cause I spend a lot of money and the same problem is coming back over and over again. Please send me a mesage to simonamathe@yahoo.com. Thank you.
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