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.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

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 . 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.

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1989 300CE Astralsilber/Schwarz
1992 300CE Schwarz/Schwarz

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,

__________________
Check out my website photos, documents, and movies!

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.

__________________
2005 Mercedes C230k sport sedan, 6 speed
1987 Porsche 924S - 968-engined track car

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.

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.

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1989 300CE Astralsilber/Schwarz
1992 300CE Schwarz/Schwarz

Here is the list of 143 amp alternators:

Engine -----Model-------Year ------Application-------------Amp kW/HP ----SysMf --Plug Conf. --- Reman Alt.
5.0L-V8 --- CL500 ------ 98-------- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
6.0L-V12 -- CL600 ------ 99-98 ---- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
4.2L-V8 --- S420 ------- 99-96 ---- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
4.2L-V8 --- S420 ------- 95-94 ---- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
5.0L-V8 --- S500 ------- 99-------- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
5.0L-V8 --- S500 ------- 98-96 ---- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
5.0L-V8 --- S500 ------- 95-------- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
6.0L-V12 -- S600 ------- 99-98 ---- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
6.0L-V12 -- S600 ------- 97-96 ---- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
5.0L-V8 --- SL500 ------ 98-95----- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
6.0L-V12 -- SL600 ----- -99-98----- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X
6.0L-V12 -- SL600 ----- -97-96----- Bosch 143A ----------- 143 ----------- BO ---- B19 --------- AL0162X

***There was also a 115 amp in 1997 for the S420 and a 120 amp in 1994-1995.

BO=BOSCH

Voltage Regulator Plug Identification


Bosch = Mercedes
AL0162X = 009-154-56-02
AL0162X = 009-154-67-02
AL0162X = 010-154-71-02

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1989 300CE Astralsilber/Schwarz
1992 300CE Schwarz/Schwarz

I'm not too picky on wire brand, as long as it's not junk. Be careful to route the wire away from anything it could rub on and wear through the insulation.

As for terminals, you'll want to figure out what size cables need to be attached at the battery, and buy a terminal that will accept all the sizes you need for YOUR setup. The stock wire to the starter will fit into a 4ga or 2ga hole. I needed a terminal with holes for one 0ga (to alternator), one 4ga (to starter), another 4ga to my headlight relay fuse block, and one 8ga (to the block that feeds the rest of the car). You may need something different. I got mine here:


http://www.cardomain.com/shoptype/Battery+Terminals

I think this is the one I used on my blue car:
http://www.cardomain.com/item/STISBTMP

Thank you for all the help . My car didn't even start today after putting in the new volatge regulator yesterday. I want to go shopping for the wires and connectors tomorrow so that I can have everything ready for when the alternator arrives.

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1989 300CE Astralsilber/Schwarz
1992 300CE Schwarz/Schwarz

Serpentine belts only.


No idea. Every car is different. Maybe, maybe not. You'll find out when you test-mount it. Not a big deal.


I forget exactly... approximately 6 or 7 feet, I believe?


Yes, that's the one I have in my 300D with an OM603.


For a photo of one of the "very late" alternators, click here. That one is from a G55 AMG. Notice the two-pin, flat-blade VR connector instead of a single threaded post for the 'D' terminal - that's the difference.


Anything except the 'very late model' ones will definitely fit.


Don't forget you need a core to get the 'reconditioned' price - you have no core to return. In the USA, some are available for $300-$400 rebuilt, even without returning a core. Much preferred, IMO, to just buy a used one for $100-$125.

__________________
Check out my website photos, documents, and movies!

Last question ..... looking at Post #1 and Post #15, will all of these 150 amp alternators fit? Are these one that I listed considered the old style?


Thank you very much for answering all those questions

__________________
1989 300CE Astralsilber/Schwarz
1992 300CE Schwarz/Schwarz

I just bought a 150 amp alternator and I should get it on Friday or Monday. Is there a good brand or better brand of cable and connections? Where should I buy these from?

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1989 300CE Astralsilber/Schwarz
1992 300CE Schwarz/Schwarz

gsxr I've tried the 2-prong 150A alternator in my M103 Brabus and although the alternator itself worked perfectly the VR was doing nothing. I had the alternator in my car for a few months before realising this. Only the handbrake and ABS lights were self-testing on ignition. On fitment of an older 150A alternator all dash lights started self-testing again. I may have blown my ABS ECU finding this out though as my ABS light is coming on after 10mph, my OVP is new and fuses are fine.