Bimmerfest - BMW Forums - View Single Post - Anyone know what's going on?
View Single Post
Old 12-04-2012, 04:38 PM
pablo645's Avatar
pablo645 pablo645 is offline
Officially Welcomed to the 'Fest
Location: NY
Join Date: Feb 2009
Posts: 1,998
Mein Auto: 650i Convertible
Originally Posted by petriej View Post
Once the car is running, all electrical power is effectively delivered by the alternator. Your symptoms are a tell tale sign the alternator is going bad, not the battery going bad.
+1. I would have the alternator checked. You could do it if you have a multimeter as well. If you connect the leads to the ground (Car frame) and to the +Pos terminal before starting the car, you should be reading battery volatge of 12V DC. Then start the car and you should see the voltage go up to approximately 14V DC. this should remain a constant value. If the volatge is irratic, then the alternator regulator might be bad. (I'm going by memory here so bare with me )
2012 650-xDrive Convertible. Titanium Silver Metallic - M Package - Driver assist package- Cold weather package - luxury seating package - Bang & Oulfsen system.

Previous Cars:
2008 650 Convertible 6 speed manual
2004 645 Convertible 6 speed manual
1994 540 6 speed manual
Reply With Quote