Got a solid red battery light on the drive home today. Battery is not that old, and reading the voltage via the dash says just over 12v when car is off, 12 when running. So dead alternator then? as far as I know that is original at 170,000km.
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Be glad you made it home in the M. When my alternator went, it gave me about a 5km heads up (dash lit like a Christmas tree and motor missing big time). I suggest you don't drive it again and get a tow while in the comfort of home and not stranded on the road. -
Lol I got blessed with 2 bad alternators within a couple years of each other, both of which left me stranded. I miss those days.2003.5 MT JB/B - CSL SCHRICK SUPERSPRINT EISENMANN JRZ SWIFT MILLWAY APR ENDLESS BBS/SSR DREXLER KMP SACHS RECARO AR SLON MKRS GSP DMG KARBONIUS CP AUTOSOLUTIONS KOYOComment
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Jimbo's M wow, I drove about 20km with the light on before I got home and parked it up. No misfires or lights other than the battery light itself. Didn't plan to drive it obviously, don't want to get stranded anywhere. I will swap the alternator myself so no need to get it towed from here, just want to confirm alternator is the likely culprit before I get one from FCP.Comment
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Obviously you'll need to diagnose further, but it's a good bet.Originally posted by Thoglan View PostComment
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Res battery light = alternator.
alternator is one of those items where you should pony up for the actual BMW branded part, or you’ll be doing it repeatedly.
2005 IR/IR M3 Coupe
2012 LMB/Black 128i
2008 Black/Black M5 SedanComment
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I would go for one of the brand new Valeo units. The bmw units are still reman’d.Originally posted by Obioban View PostComment
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Yuuuup.. 2 years ago i got a reman and it was shit. Bmw doesnt like reman. Get Valeo from FCP, cant go wrong with lifetime warranty on sometging like that! And price is one of the lowest.Comment
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Seems FCP doesn't offer the valeo part any longer. Only Bosch and bmw.Originally posted by pawelgawel View PostComment
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Manual or SMG? If it's a manual I would think it should last more than 170,000Km. My previous E46 323iT lasted 180k miles before I was about to change the worn brushes but then it was totaled.Originally posted by Thoglan View Post
This is unusual long range for a dead alternator.Originally posted by Thoglan View Post
Let engine idling and measure volt at the big cable bolted to the rear of the alternator -- should be close to 14v.
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When my red battery light came on I had about 30 miles and 2 days until my car was not drive-able. Good thing is it’s an easy diyComment
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Speaking from experience, if you have a good battery it's doable to drive that distance. Especially if you consciously reduce the electrical load on the battery. I was watching my voltage drop live, but it did manage to go a surprisingly long distance.Originally posted by sapote View PostComment
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Similarly I managed to get home some 15km at night so lights on, when mine died. Had an open circuit rotor winding from memory. Tried to get parts to repair it, but supplier didn't deliver so bit the bullet and went brand new
Replaced with a Valeo (from ECS) about about 4 years ago which was a drop in as my original was a Valeo I'm pretty sure. Been going fine since.Comment
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Yep bad alternator. Replace it with a new oe unit and all shall be well
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Been there. FWIW I went with a Bosch remanufactured alternator from FCP about 20-25k miles ago(?) and my car is currently experiencing a fault code "vehicle power over 18v" which is likely a bad voltage regulator. There is no battery light but I feel it's inevitable, and I've spent enough time with my cars on flat beds lately. I'll get another one of the same from FCP since it will be free, do it preemptively, but I wonder in hindsight if the OEM BMW branded one would have been a better call for longevity.Comment
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