Red battery light on.Help!

[SlickGT1]

Yea I said $15, just because I forgot. But this is it at auto warehouse.
BMW X5 Voltage Regulator - Free Shipping - Bosch, OES Genuine

That being said. Get the oe BMW one even cheaper through Craig at Openroad BMW. It is a fraction of the cost of an alternator.

[jdstrickland]

Originally Posted by four.8is

Changed the battery with a fully charged one.
Unlocked the OBC, test 9 and got 11.4 V
Turned on the AC, and it went to 10.9v-11.0v
So I guess I need to rebuild the alternator.

Unless the engine is running, you know nothing about the status of the alternator.

Start the engine and measure the voltage, you should see something in the range of 14.5v, give or take a few tenths.

[four.8is]

Alternator is not rebuildable, gotta get a new one...
In the process of removing it, the brittle nipple on the plastic connector where the small hose connects the upper rad hose and expansion tank broke off, not sure if I should glue it back on until I tackle the whole cooling system?

Power steering hoses leak like crazy...oh well...one job at a time.