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Old 1st January 2021, 04:59 PM
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Ronin Ronin is offline
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Default Decent alternator brand?

Alternator in my 2,8 AMX randomly drops out/stops charging, regardless of engine rpm, so I'm looking to replace it. The part number is 078903016H I believe, but there is so many aftermarket brands with such a big price range I'm not sure what to chose. I think Valeo is the oem brand but they want like 500, while a Bosch equivalent is 160.. What would you go with?
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Old 1st January 2021, 06:29 PM
Audifan Audifan is offline
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Maybe just need to replace the voltage regulator on the alternator instead of replacing the whole unit?
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Old 1st January 2021, 06:32 PM
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Originally Posted by Audifan View Post
Maybe just need to replace the voltage regulator on the alternator instead of replacing the whole unit?
Hmmmm. I'd rather replace the whole thing and be done with it for ever.
But if it can be done without taking the alternator out, it may be viable, do you know what part number it is?
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Old 1st January 2021, 08:01 PM
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I'm not sure how accessible it is. I've done this in the past with a couple of my old Audi cars and I was lucky enough where I had just enough room to replace the voltage regulator without removing the alternator. There are a few part numbers but I'm not sure which one you will need 028 903 803 E, 00A 903 803 A, 06B 903 803 B as I got these numbers from this site
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Old 1st January 2021, 08:28 PM
MikkiJayne MikkiJayne is offline
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There are three different alternators for the 2.8 - 120A Bosch (078 903 016F), 120A Valeo (078 903 016H, and 150A Bosch (078 903 016). I think we just got the 150A in the UK but I'm not 100% on that. Big Red and the other FL 2.8s I've had have had the Bosch 150.

120A Bosch regulator is 038 903 803E
120A Valeo regulator is 06B 903 803
150A Bosch regulator is 028 903 803D
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Old 2nd January 2021, 11:18 AM
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homer simpson homer simpson is offline
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Why not get it refurbished? There is a company local to me who will replace what needs replacing. I have used them twice and no complaints. Reasonable prices too. Worth a call.

http://www.sacweb.co.uk/alternators.html
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Old 2nd January 2021, 12:15 PM
ainarssems ainarssems is offline
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On my A6 when the alternator failed I just replaced regulator with bushes. The main reason was because I could do it without taking alternator off so it was less work. 2nd reason was that I could choose the regulator voltage for the aftermarket regulators so I went with a bit higher voltage than stock and chose 14.8V.
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Old 3rd January 2021, 05:10 AM
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Quote:
Originally Posted by ainarssems View Post
On my A6 when the alternator failed I just replaced regulator with bushes. The main reason was because I could do it without taking alternator off so it was less work. 2nd reason was that I could choose the regulator voltage for the aftermarket regulators so I went with a bit higher voltage than stock and chose 14.8V.
That's interesting, Ainars. Do you know/remember what the standard alternator output is? I seem to recall 14.4V but I may be wrong.
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Old 3rd January 2021, 10:57 AM
ainarssems ainarssems is offline
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I think stock is about 14-14.4V . I think some are supposed to be temperature dependant as well giving more voltage in winter, not sure how that works as when the engine warms up generator is a lot warmer than the battery.
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