[magnetic1]

Originally Posted by Chaser720

For people looking to go used/rebuilt on these... IMHO dont. I tried to save a buck and it took me three rebuilt ones to get one that actually worked right. Not worth the hassle.

Even the ones you get from the dealer are reman units

[MisterEm]

If you don't have an electrical rebuild shop nearby... get the OEM one from rmeuro:

http://www.rmeuropean.com/bmw-parts.aspx#Category

Same Bosch Alt. the stealer (and Tischer) charge $450 for.

Added bonus: California, Arizona and Nevada get free overnight delivery with GSO as well. Just type GSO shipping in the notes page.

Mike

p.s. My original alternator rebuilt at the local ma and pa shop electric rebuild shop (for less than $100 with tax) is nearing 50k miles.... The only thing unique about these M3 alternator units are the mounting holes. Same crap that goes on an old F150.

[AW_IRed]

Ok. I just ordered Bosch alternator. Drove the car today, rev'ed it a few times all the way to 6k+ rpm, didnt see the battery light flash. Weird. It was almost always flashing when i hit 5k+ rpm a few days ago. any ideas? thoughts? TIA.

[Jeka///M3]

Just had the same issue a couple of weeks ago. The light would come on at hi RPMs, and eventually just stayed on.
I got a used unit from my body for $180 and installed it the same day.

Our alternators are not the problem, it's the voltage regulators (which are a part of the assembly). there is a transistor that powers up the rotor (basically an electromagnet) of the alternator, and by varying the current to the rotor the stator output voltage gets regulated.
So the Alternator itself almost never goes bad, and any alternator you buy either from the dealler or any other place has a refurbished voltage regulator.

[magnetic1]

Originally Posted by Jeka///M3

Just had the same issue a couple of weeks ago. The light would come on at hi RPMs, and eventually just stayed on.
I got a used unit from my body for $180 and installed it the same day.

Our alternators are not the problem, it's the voltage regulators (which are a part of the assembly). there is a transistor that powers up the rotor (basically an electromagnet) of the alternator, and by varying the current to the rotor the stator output voltage gets regulated.
So the Alternator itself almost never goes bad, and any alternator you buy either from the dealler or any other place has a refurbished voltage regulator.

Not entirely true. While that may be the case in some instances, it wasnt for me. I replaced the voltage regulator first and it didnt fix the problem. Replaced the alternator and all is well now. Keeping the new OEM voltage regulator in trailer though as backup.

[m3vert7590]

this just happend to me and i replaced alternator and regulator... and a day later its happening again.. and its a brand new alternator and regulator.. my batter light flashes on past 4k rpms .. its only been 3 days since replace alternator

[m3vert7590]

now im completely pissed off

[MisterEm]

Originally Posted by m3vert7590

this just happend to me and i replaced alternator and regulator... and a day later its happening again..

Take your battery out and give it an overnight trickle charge from a proper battery charger. The alternator will not charge up the battery to full capacity by driving alone, if its charge state was diminished from a bunked alternator.

[magnetic1]

Originally Posted by MisterEm

Take your battery out and give it an overnight trickle charge from a proper battery charger. The alternator will not charge up the battery to full capacity by driving alone, if its charge state was diminished from a bunked alternator.

That too. There is a big warning tag on the Bosch reman alternators that state you must fully charge the battery before hooking up the alternator or else it could fail.

[AW_IRed]

I used to only get battery light flashing when doing 5k+ revs. But now, battery light is on right on starting the car. Alternator and more stuff now??