1997 BMW Z3 Battery light stays on

1997 BMW Z3
132,000 MILES • 6 CYL • 2WD • AUTOMATIC
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DAVIDSLAYNE
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  • 4 POSTS
My battery stays on so i replaced the alternater and i have the same issue what else could it be
Jun 3, 2010 at 10:17 PM
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DOCHAGERTY
  • ASE Certified Mechanic
  • 9,606 POSTS
  • ASE Certified Mechanic
Did you check the battery voltage with the new alternator? Where did the replacement alternator come from, was it a new unit or remanufactured?
Jun 3, 2010 at 10:52 PM
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DAVIDSLAYNE
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Yes i checked the new alternater it is puting out 14 volts and i is a Bosch remanufactured alternater.
Jun 4, 2010 at 2:58 PM
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DAVIDSLAYNE
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  • 4 POSTS
yes the test on the battery was 12.4 volts and the alternater is puting out 14 volts
Jun 4, 2010 at 3:00 PM
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DOCHAGERTY
  • ASE Certified Mechanic
  • 9,606 POSTS
  • ASE Certified Mechanic
If the system is getting 14 volts with the new alternator and the light is still on, the wiring might be suspect. The blue wire at the alt. is one side of the light and battery voltage is on the other with the key on. When the alt. is not turning the blue wire is not hot and lets battery voltage illuminate the light, when the alt. is working, the blue wire has battery voltage, and the light is out.
Jun 7, 2010 at 10:05 AM
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DAVIDSLAYNE
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  • 4 POSTS
The blue wire stays on and the green has no power at all with car running or with the key on or not. Is it fused or a relay possable.
Jun 7, 2010 at 6:35 PM
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