Years ago on my 02/98 M3 the original alternator failed with only 28kmiles, battery light was always dimming, checked with multimeter, only around 10V with engine running, replaced voltage regulator, no change. Finally found out that 1 or 2 diodes had died. Replaced the alternator with a 140A used one since then. Some years ago I tried to disassemble the rectifier to get to the diodes as these are available as single items. But the rectifier pack seems unserviceable, I cracked the housing and had to scrap the rectifier.
Now I am trying to rebuilt the alternator for stock and need a source and a part number for the correct rectifier diode pack, ETK does not show it as single item. I hope someone here on the forum knows a source plus correct part order number.
Data of the original alternator: Bosch 80A , BMW 12311744564, Bosch # 0 120 485 048. KC>14V 50-80A, Made in Great Britain, BMW # 1744562, Accdg to ETK new # 12311744562, 12341234667, remanufactured 12311744566
http://bmwfans.info/parts-catalog/E3...ctrical_system
Pics of the defective rectifier below.
Checked Woodauto in U.K. if they might have something, but ...apparently not https://www.woodauto.com/group/82/RTF---Rectifier
On the other hand a new rectifier costs usually about $60, a reman alternator might be another option
The same alternator is used in E36 M50, M52, S52, M3 and in E34 with M50 engines, that is why I post a copy here too in the E34 forum, for info
Last edited by shogun; 04-12-2019 at 10:35 PM.
Shogun tricks and tips for the E32 series are HERE!
Inquiring minds (mine anyway) want to know...
What purpose would a rebuilt 80A alternator serve when you've already installed the 140A unit?
Did the 140A unit make the car run better in any discernable way?
Will the effort be worth more than a professionally rebuilt 80A alternator?
Can you trace to the OE supplier?
As widely used as it seems to have been, surely someone will turn up with one that's just been sitting about. Shipping to Japan gonna cost, though, and might make the project economically unfeasible.
Charlie
Your mission, should you decide to accept it, is to add value to these threads, either by pictures or by descriptions, so the next person with the same or similar problem stands on your shoulders.
Want to rebuild the 80A for stock/stand-by. There is no noticable difference between the 80A and the 140A alternator, both supply enough power for the car in use.
that I will only know when I know the price of a new diode pack rectifier, and repairing DIY is my hobbyWill the effort be worth more than a professionally rebuilt 80A alternator?
so far notCan you trace to the OE supplier?
product details 0120485048 https://www.bosch-automotive-catalog...uct/0120485048
replaced in 2916 by Bosch 0986039100
BMW 12 31 1 730 602
BMW 12 31 1 730 580
BMW 12 31 1 744 564
BMW 12 31 1 744 562
BMW 12 31 1 744 560
BMW 12 31 1 735 792
Last edited by shogun; 04-14-2019 at 08:29 AM.
Shogun tricks and tips for the E32 series are HERE!
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
Checked that already and asked on the German forum, nothing does fit by part number. In most of the offers they mention " fits for Bosch p/n ...", but my Bosch alternator number is not mentioned
Shogun tricks and tips for the E32 series are HERE!
Filtering by year/make/model, this rectifier comes up under the alternator parts list.
https://www.aspwholesale.com/alterna...er-p16597.html
Part numbers don't match, but it looks identical. May be worth doing a little digging around and searching with the various BMW/Bosch part numbers to see if you can make a connection.
85 325e m60b44 6 speed / 89 535i/5
e30 restoration and V8 swap
The finished product!
Would a rectifier pack for a 90A alternator work? I can't find anything for the 80A for the m50 engine but I can find it for the 90A.
Price is about 100€ sourced in Germany.
Bosch part # 1127320734
Does not fit based on info I found. Might be easier just to buy a cpl. one instead of a rectifier.
On the chinese auction platform they sell these and mention where it fits: ALTERNATOR RECTIFIER,RB-49H,136485,1127320717,1127320726,1127320734,112732 0740,1127320935,0120468042,0120468043,0120468061
Brand Name: AKNCOK Model Name: 0120468062,0120468063,0120468064 ,ALTERNATOR RECTIFIER,RB-49H,136485, 127320717,1127320726,1127320734,1127320740,1127320 935,0120468042,0120468043,0120468061,0120468062,01 20468063,0120468064
Features:120mm OD ,6-35 Amp Diodes ,Reference Numbers: BOSCH 1127320717,1127320726,1127320734,1127320740,112732 0935 ,CARGO 136485 ,Mobiletron RB-49H
For use on alternators: BOSCH
0120468042,0120468043,0120468061,0120468062,012046 8063,0120468064,0120468075,0120468076,0120468077,0 120468078,0120468102,0120468103,0120468104,0120468 105,0120468110,0120468111,0120469004,0120469005,01 20469006,0120469007,0120469868,0120469869,01204698 76,0120469877,0120469901,0120469902,0120469906,012 0469907,0120469911,0120469912,0120469966,012046996 7,0120469968,0120469969,0120469973,0120469974,0120 469984,0120469985,0123510017,0986035740,0986036760 ,0986038330
Last edited by shogun; 04-14-2019 at 06:46 PM.
Shogun tricks and tips for the E32 series are HERE!
OK, I've been looking around using the bosch# 0120485048 that you posted.
I've come across this part on ebay.de that references this bosch part #. Have a look and see if it might be the correct one.
https://rover.ebay.com/rover/0/0/0?m...2F223475902162
Outside of that, I have a good friend who works for bosch here in Vaihingen and deals with the development and testing of such things as abs, esp etc... I could ask him to check it out.
Looks like you might have found your answer 8 years ago... haha
https://www.bimmerforums.com/forum/s...7#post23167487
85 325e m60b44 6 speed / 89 535i/5
e30 restoration and V8 swap
The finished product!
yeah, getting old and forget, looks like 8 years ago I was not yet 100% sure for the 80A rectifier, and the project was sleeping since then. Dats found the right rectifier for this 80A one, I checked more and the Ebay offer is from a starter and alternator supplier in Poland, here more details on their website for the rectifier https://en.as-pl.com/p/ARC0031
Reference number
1127319009 BOSCH
1127319617 BOSCH
1127319623 BOSCH
1127320862 BOSCH
1127320882 BOSCH
and the pdf file there shows the Bosch alternator number same like my one
0120485048 BOSCH
012048504J BOSCH
0123100002 BOSCH
0123120001 BOSCH
0123310006 BOSCH
0123315004 BOSCH
0123320012 BOSCH
9120485048 BOSCH
9123320012 BOSCH
9123690001 BOSCH
Last edited by shogun; 04-15-2019 at 09:16 AM.
Shogun tricks and tips for the E32 series are HERE!
got the part number for the diode pack from Germany, original Bosch # for Diode Pack for Bosch alternator 0 120 485 048, KC (R) 14V 50-90A is Bosch 1 127 319 816. Just for future reference
Shogun tricks and tips for the E32 series are HERE!
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
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