I have tried to search my problem

[USTrucker]

2004 525i m54. My alternator is not charging my battery. I have purchased a new bosch alternator, it seemed to work for a bit. But is not charging now. I never got an alternator fault light on my dash. Battery checks out as good. I can put a charger on and it will start and run. I have a bluetooth code reader, that can monitor stats while running and it shows the battery is not getting a charged. The fault codes I am getting are 281D- DME: BSD generator signal; 29A8-DME: power management, vehicle electrical system. What am I missing here?

[Sleepyhead97]

Have your battery load tested. Could be bad

[jclausen]

Check the sensor on the battery cable

[pshovest]

How many miles?
Did you have the same codes BEFORE you replaced the alternator?
Any chance you installed an E39 525 alternator which doesn't support BSD communication? Confirm the alternator PN is correct for your car.
Check for water and wet modules under the spare tire.

[USTrucker]

I had the battery load tested. It is good per my og post.

What sensor on battery cable?

98000 miles
Yes I had same codes before. It is not an e39 alt, e39 does not have mount for extra pulley.
I did check for water under spare it was dry, also module was dry and moved up to trunk not under spare anymore.

If I charge battery, it does not have a parasitic discharge. I charged battery friday after I got home from work, took it off charger saturday morning. Left car alone until monday morning when I went to work, started right up no problem.

[jclausen]

The negative cable has the sensor I believe

[USTrucker]

How are you supposed to check it, to see if it is good?

[USTrucker]

Ok I disconnected the IBS, nw the alternator is charging the battery. Can the IBS be left disconnected for good or will it hurt the car?