Alternator Options - I need Help!!
 

If any of you already read my other post today, you probably know why I'm typing this one right now.

I want to get a new alternator for my 1989 300ce. Here is some information on my alternator:

Engine ----Model-----Year --------Application ------ Amp kW/HP --- Sys Mf ----Plug Conf. ---- Reman Alt.
3.0l-L6 --- 300CE --- 89-88 ------ Bosch 70A ------- 70------------ BO -------- B15 ---------- AL65X --------(*108)

BO=BOSCH

*108 -BOSCH/VALEO Notice of Interchangeability
This alterantor came as original equipment in both Bosch and Valeo versions. The two types of units are different in physical appearance, but are totally interchangeable in both fitment and appearance.


Voltage Regulator Plug Identification
http://img276.echo.cx/img276/4775/dsc0190416jd.jpg

Here are the highest output alternators Mercedes makes that I was able to find. All 150A :

Engine -----Model-------Year --------Application -------- Amp kW/HP --- SysMf --Plug Conf. - Reman Alt.
4.3L-V8 --- C43 ------- 00-98 ------- Bosch 150A ---------- 150 -------- BO ---- B19 ------- AL0766X
4.3L-V8 --- CLK430 ---- 01-99 ------- Bosch 150A ---------- 150 -------- BO ---- B19 ------- AL0766X
4.3L-V8 --- E430 ------ 01-98 ------- Bosch 150A ---------- 150 -------- BO ---- B19 ------- AL0766X
5.5L-V8 --- E55 ------- 00-99 ------- Bosch 150A ---------- 150 -------- BO ---- B19 ------- AL0766X
5.5L-V8 --- CL55 ------ 02-01 ------- Bosch 150A ---------- 150 -------- BO ---- B19 ------- AL0766X
5.5L-V8 --- S55 ------- 02-01 ------- ALL 150A ------------ 150 -------- BO ---- B19 ------- AL0766X
5.0L-V8 --- SL500 ----- 01-99 ------- Bosch 150A ---------- 150 -------- BO ---- B19 ------- AL0766X
http://img74.exs.cx/img74/8813/DSC01901.jpg

Engine -----Model-------Year ------Application-------------Amp kW/HP ----SysMf --Plug Conf. - Reman Alt.
5.0L-V8 --- CL500 ------ 01-99 ---- Bosch 150A ---------- 150 ----------- BO ---- B19 --------- AL0768X
4.3L-V8 --- S430 ------- 01-00 ---- Bosch 150A ---------- 150 ----------- BO ---- B19 --------- AL0768X
5.0L-V8 --- S500 ------- 01-00 ---- Bosch 150A ---------- 150 ----------- BO ---- B19 --------- AL0768X
http://img74.exs.cx/img74/4773/DSC01900.jpg

Engine -----Model-------Year ------Application------------Amp kW/HP ----SysMf ---Plug Conf. - Reman Alt..
5.5L-V8 --- ML55 ------ 01-00 ----- ALL 150A ------------ 150 ---------- BO ----- B19 --------- AL0785X
4.3L-V8 --- ML430 ----- 01-99 ----- Bosch 150A ---------- 150 ---------- BO ----- B19 --------- AL0785X
http://img74.exs.cx/img74/4317/DSC01902.jpg

Voltage Regulator Plug Identification
http://img276.echo.cx/img276/1607/dsc0189812ti.jpg

Cross Reference
Bosch = Mercedes
AL0766X = 0-123-520-006
AL0785X = 0-123-520-012
AL0768X = 0-123-520-017

Which one of these will fit?
What modifications might I have to do to the pulley or plug or anything else?
Are the brackets from my alternator the same size as the 150A versions?

if it doesnt make noises you just need a new volt reg , 20 bucks on ebay

or get it rebuilt at a local shop , 80 bucks

I figured since my alternator is only 70A that I maybe an upgrade would be better option. I just asked someone who has one for sale on ebay and he said that the 150A won't work on my car, because the voltage regulator hook ups and operation is different, so is the physical size.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7974975537

Does anyone know if what he said is true?


Has anyone tried or even seen one of these:
http://www.hap.com/products/Alternators/Water/index.html

I have an 83 300CD and the original 45 amp alternator was not sufficient for my needs (big stereo) and with some research found that an early Saab 9000 115 amp alternator (AL129x) fit in with some minor alteration. It is by the way the same case style as your original. I had to convert the twin B+ terminals to a single ring terminal to adapt to the new configuration. It actually was a tight fit but that was mostly because of brand new fan belts I had installed. I am not sure this is what you want to do but it seems you are looking for alternatives to the original alternator.

First find out if the alternator is defective.

Second find out if there is a load on the alternator
when the car is stopped and closed up (that is,
when it is closed up for the night). You would need
to measure the current through the battery for this.

Third have the battery checked to see if it is ok.

I wouldn't think that replacing the alternator
is going to help you any if the battery is bad or
there is a load that shouldn't be there on the
battery.

I would think that replacing the alternator with any
working alternator would fix the problem if the alternator
is bad, and I would think that replacing it with the OEM
would be best.

I do not see that replacing the alternator with a bigger one
would help except in some bizarre circumstances. Namely
if you are using more than the current alternator would provide when driving around or if you are discharging your battery
during the night and then only driving it a short way during the day.

I must admit I've only read your original email only once and might have missed something.

According to my book, your Saab 9000 115 amp alternator (AL129x) came on the 1988-1990 model years. Standard that car came with an 80A. The one you have is the optional version. It has the same B19 Voltage Regulator Plug Identification as the Mercedes 150A. Your car has the same B15 that I have on my 300ce. Out of curiousity, why did you choose a Saab alternator and not another Mercedes? Other than converting the twin B+ terminals to a single ring terminal to adapt to the new configuration, what else did you have to do?

You also had to change over the pulley as on the Saab it was a single belt and mine was double...The issue with using Saab instead of Benz is that most Bosch alternators of a certain vintage are the same, it is the car that is different. Many actually have the same case it is the guts and voltage regulator that are different. I actually got the idea from this forum as a successful changeover to the higher amperage unit...

Found great link!
 

I found a great thread by GSXR / Dave M. The upgrade is possible and he is the proof!

http://www.peachparts.com/shopforum/car-audio-multimedia/53236-installed-143a-alternator-my-w124-86-95e-class-photos-post444946.html

Anything is possible, but the no brainer is to replace the 70A with a 80A, that is used on a 90- 300E. I think the number is AL66x and it should even be a few pennies cheaper.

So you say a 15% increase isn't worth foolin with, well the rating is only a part of the story. The 80A alternator is a different design and puts out about 60A at idle while the 70A one puts out about 30.

Its a straight bolt up deal and if you aren't up to changing the connector ends a new harness can be bought from MB for around $50 last I checked. The harness goes from the alt to a connector buss by the battery, simple to change. We used to change the harness but recently we aquired proper terminals and just solder up the new ends. About the same time as changing the harness. If you don't get proper ends I would go for the factory harness.

Thanks Steve. I didn't realize how much of a difference the 80A is over the 70A. The proper terminals you mentioned are they a Mercedes part or aftermarket? I called the dealer today and they quoted me $200 Canadian for teh harness :eek: . Big difference from $50.

Did you check out post #8? Do you think that the 150A is not as easy as switching the pulley and connections like GSXR says or do you forsee any potential problems? It will cost me around the same money to get which ever alternator I chose in the end, so why not go for the best.

Hi everyone,

The Saab setup is, I believe, desireable for OM61x or M117 cars with V-belts. You can't use a late-model serpentine belt alternator on a V-belt car, that's why the Saab units are handy - if you can find one.

For Mercedes with serpentine belts and dinky 70-90A alternators, the 143A or 150A units are the hot ticket. It's a straight bolt-up BUT there are the following caveats:

1) You need to use your original pulley! Sometimes it's nearly impossible to get the pulley off your old alternator. In that case buy a new one for *your* car and swap it onto the 143 or 150 unit. Costs about $30 for a new pulley. I had to do this on one of my alternator upgrades.

2) You may need to re-clock the big alternator. That means removing the 4 screws that hold the two halves together, gently pry it apart, turn the rear half so the big battery terminal is in the optimum position for YOUR car, and screw it all back together. On a rusty used unit, this can be a real chore. On a super clean used, or rebuilt, this is easy. Shouldn't be any problem on a 6-cyl car but on an M119 engine, even with re-clocking the clearances can be really tight - trust me, I did it on my E500 with a 150A unit.

3) You need to toss the stock wiring harness to the battery and fabricate your own with heavy cable. This is not difficult, but if you're not handy with large electrical connectors, have it done at a pro car stereo shop. Use 4ga at a minimum, preferably 2ga, and 1/0 (pronounced 'one-ought', or zero gauge) is about the biggest you can realistically use. Custom battery terminals are required, etc.

4) The very late model 150A alternators, as shown in that auction linked above, have a different voltage regulator. I do not know if these will work with older cars (1986-2002) or not. They may, they may not, until someone tries it we'll probably never know. I have the part numbers for the special 2-prong VR connector required, if anyone wants to experiment... they're only a few bucks. The auction closed ridiculously cheap! Too bad I missed that. :(

Photos of my installations are here:
http://www.w124performance.com/images/W124_stereo/alternator/


Best regards,

Dave,

How did you remove the alternator pulley?

Thanks,
Karl

I recently swaped the Bosch alternator on my porsche and had to reuse the old pulley, and it was a beeotch to remove, I finally got it off with some PB blaster, let it soak for 15 minutes, and a small pry bar. I had to use mallet to flatten out those cooling vanes that spin around because the removal bent them a little, but it was pretty easy. someone told me to use 2 or 3 jaw puller, but the one i had was too big to use to remove pulley.

The problem I had with the pulley was removing the nut. It's nearly impossible without an impact wrench, or without damaging something. On mine I used a pneumatic impact gun, solvent, a propane torch, and even a left-handed monkey wrench to no avail. It was a rebuilt unit, I wondered if the rebuilder used red Loc-Tite or something on it. On all the used 143 or 150 amp units I've bought, the nuts spun right off with the inpact gun. Not sure if they would have come off so easily with just hand tools...

Once the nut is off, the pulley pops off the shaft easily, no pullers required.

:o

First of all, many thanks to you for sharing those pics and your wisdom on this subject ;) .

First question...Did the W124 cars come with V-belts or just serpentine belts?


Is it necessary to re-clock the big alternator for my 1989 300ce?



Do you know how long the cables must be?


The alternator you have in the link titled "150A_b.jpg" is part number 010-154-83-02. That is supposed to be the same as Bosch AL0785X in my chart. Is this the one you used on one of your cars?

Which ones are "The very late model 150A alternators..." ? What I'm asking is which alternators from the ones I have listed will fit my 1989 300ce?


I called the dealer and checked the prices on the alternators...just for fun. Prices are in Canadina dollars and before applicable taxes. Here is what I was quoted:

ALO766X = MB 010 154 29 02 $1267.00 Canadian for new and is $568.00 for reconditioned.
ALO766X = MB 010 154 68 02 $1283.00 Canadian for new and is $N/A for reconditioned.
ALO768X = MB 011 154 32 02 Part number changes up to NLA for new and is $557.00 for reconditioned.
ALO785X = MB 010 154 83 02 $1235.00 Canadian for new and $557.00 for reconditioned.