This is actually happening on my E 46, but the issue would be the same if it was on an E9. At least one that had the voltage regulator updated to inboard with the alternator.
This is a 2004 325i touring with 160,000 miles. Recently I noticed the battery light came on. So I put my little voltage meter in the cigarette lighter to figure out what was going on. What seems to be happening is that 50% of the time the voltage will be at 13.8, indicating a healthy charging system. But every now and then for no apparent reason, the voltage suddenly drops to between 11.5 and 11.9 and the battery light obviously comes on. At some point 10 minutes later, it may then for no apparent reason jump back to a normal 13.7.
So it seems that either the alternator is cutting in and out, or the voltage regulator is having a problem. Before I go ahead and spend close to $200 for a rebuild alternator, does anyone know if there might be an easier fix?
Thank you.
This is a 2004 325i touring with 160,000 miles. Recently I noticed the battery light came on. So I put my little voltage meter in the cigarette lighter to figure out what was going on. What seems to be happening is that 50% of the time the voltage will be at 13.8, indicating a healthy charging system. But every now and then for no apparent reason, the voltage suddenly drops to between 11.5 and 11.9 and the battery light obviously comes on. At some point 10 minutes later, it may then for no apparent reason jump back to a normal 13.7.
So it seems that either the alternator is cutting in and out, or the voltage regulator is having a problem. Before I go ahead and spend close to $200 for a rebuild alternator, does anyone know if there might be an easier fix?
Thank you.
