Several weeks prior to this delayed alternator charging issue my transfer case was replaced and reprogrammed by the dealer - due to a relatively minor mishap. While waiting for my new alternator and belts to arrive I experienced a "4x4 inactive" alert on my OBC with a yellow DSC symbol light. The DSC light remained on after subsequent engine starts. On Saturday I took my X-5 back to the dealer for troubleshooting since it was under warranty support. Today the service advisor told me they read out the eletrical system and found a faulty alternator and that is what was causing the 4x4 light to come on -- even with a fully charged new battery. The dealership wanted $1550 to replace the alternator. I already had one ordered and headed my way. I was willing to allow the dealer to install my parts but it was against their policy to do so. So I paid an hour's labor @ $140.00 for their troubleshooting efforts and drove my X-5 home. On the way home I monitored the alternator charge at initial start of the day and it was 11.8v ---- not charging. Then, like clockwork, the alternator kicked in within 5 minutes and started charging at 13.9v all day. During the 30 minute trip home, the 4x4 light came back on, as well as the brake, ABS, and low tire pressure lights. All of this apparently related to a faulty alternator --- with a new fully charged baterry. Go figure this light show from a failing alternator.
As luck would have it my new alternator arrived this afternoon and I took my X-5 to my indy for replacement. I will get it back tomorrow and hopefully close the loop on this problem.
2002 BMW 330i E46
2006 BMW X-5, 4.4i N62 engine E53
Last edited by JNMNL52; 01-21-2013 at 02:13 PM.