Lots of issues with my 550i...
 

Alright. My dad and I have owned this LCI 08 550i since it was brand new, and it just hit 100k. Now, a couple months ago the alternator needed replaced. I spent a couple days in my garage replacing it (not mechanically inclined) and found the idler pulley on the OEM alternator was stripped, therefor could not get it off. I decided it was alright without one. It ran fine without it, although now I'm experiencing a burnt rubber smell and worn edges of the belt. It is also accompanied by a charging malfunction, and high battery drain warnings on the iDrive display. Could this be the problem? Or is it the battery, IBS cable, or other causes? I have an appointment for next Tuesday but I'd love to have it fixed now as I absolutely hate driving my 04 trailblazer!
Any help is definitely appreciated.
-kal

Shameless self bump...

Have you had the battery tested to make sure it is good. Usually when you have s charging malfunction it has something to do with the alternator.

No... Was going to do that tomorrow but now I can't even move the car!:( I JUST replaced the alternator (myself) two or three months ago...
I started up the car and entered the secret menu on the dash using the odometer button. The resting voltage (car not on) was 11.5. Can't start the car, battery is charging now so i will see what it goes up to while the car is on!:(

Alright.. I've run some tests (Hehe) and while running the car was about 12.5v idling. I revved the engine to about 2-3k rpms, and it went up to around 14.3-14.5 volts.
Sounds like a bad battery to me, but i'm not sure.. Help!!!!

Ok you do have a problem but which I do not know. The pulley ( Im assuming you are talking about the deflection pulley part # 11287549557) needs to be there to keep the belt on target. You said the belt edges are burning meaning the belt is not being held straight (too much slack) causing the burning smell and damage to the belt. I would go to advance auto if you need one now and pick one up for $30 and find a bolt for it.

Your volts are suppose to be between 14.2 - 14.7 i believe for an AGM which you are seeing. You either do have a bad battery or the lack of the pulley is causing a malfunction. Go get the battery tested to eliminate. If the battery is good then add the pulley if it is bad get a battery and have it programmed if it is not the same type/size. I would make sure i put a deflection pulley on too or you will have a shredded belt.

If you have not replaced the battery in the past 5 yrs then I would go ahead and replace it with the same type/size to avoid programming. Drive it a bit and see if the message goes away. You need the pulley though

Part ordered. Should be here monday or tuesday. Hope it works!!!