Installed a 143A alternator in my W124 (86-95 E-class) - with photos - Page 2 - PeachParts Mercedes-Benz Forum

AtlBenz · #16 11-07-2003, 03:24 PM

Can anybody foresee any problems if I just directly swap out the alt in my '94 E420 with a higher output one? Do I have to upgrade the wires too, or can I keep those stock?

I actually dont know how many amps my current one is rated for.

gsxr · #17 11-07-2003, 06:55 PM

Guys - sorry for the late reply. I was out of town for a few days, and forgot to respond to the previous questions (oops).

Bryan: There's a spreadsheet that I linked to earlier in this thread with MB part numbers and some of the chassis they're used on. Basically, you can get a 143A from any M119 (or M120) engine between 1996-99. If it's 1995 or earlier, it will be 100-120A, not 143A. For a 150A, you need something with an M113 engine - I forget the exact years, but very late 90's anyway. There's even a 180A unit but that's only in the W211 E55, I think, and would cost a fortune (and be impossible to locate used).

As to the distribution block & wire. Zero gauge is also referred to as 1/0, which is pronounced "one ought" (means "one zero"). The next size up is 2/0 (00), then 3/0 (000), 4/0 (0000), and beyond that the sizing system changes to circular mils (cross section area of the cable). Anyway the largest stuff commonly available is 1/0, and that's what I used - should be on the shelf at any local stereo shop for about $3-$5 per foot. This may be overkill... but IMO 4 gauge is bare minumum, 2 gauge is preferred minimum, and 1/0 would be optimum. For the distribution block & battery cable, basically you'll need to figure out what's needed for YOUR car. Photos of what worked for my 1987 6-cylinder are at the URL below. V8 models with the battery in the trunk would need to do something different, or perhaps nothing if the stock wire size is large enough (I've never worked on one so I don't know). Anyway check out the photos here:

http://www.w124performance.com/images/W124_stereo/white_87/

Adam: I added an aftermarket distribution block which let me take a couple of 4-gauge feeds in-line off the 1/0 cable. The one that worked for me was a small Lightning Audio block (from SoundDomain.com). You need to figure out what will work for you, and if you need cable that big or not. I left the factory distribution block in place, but upgraded the "feed" wire to it (had been an 8ga from the battery terminal originally, I made it a 4ga.). Here's a photo:

http://www.w124performance.com/images/W124_stereo/white_87/power_block.jpg

AtlBenz: Your E420 has an M119 engine with something like a 110-120A alternator. It's a simple, direct swap to put in a 143A or 150A. Your car has a pretty beefy cable to the battery in the trunk. I don't know where the distribution block is or what size cable goes to it, or if it's easy to upgrade. Look at it this way. You can swap alternators no problem, and then upgrade the wiring in the future if you want. Larger wire will simply reduce voltage drop (losses between the alternator output post, and wherever you're running the larger wire to - probably distribution block). You won't gain a whole lot with this (30-40A tops), but if you have Rallye headlamp bulbs or a killer stereo, that might be just what the doctor ordered.

Hope this helps y'all...

gsxr · #18 11-17-2003, 09:26 PM

I got some photos of the 143A and 150A alternators side by side (click links below). Note that the 150A unit is slightly larger, and has a lot more venting in the case. Interestingly, the 150A is a half pound lighter, possibly due to the larger vents (16.25 lbs compared to 16.75). Also note the ratings on the nameplate. The 143A is rated 73-143A, the 150A is 90-150A. The first number is the alternator's rated output at ~1800rpm shaft speed, the second number is output at ~6000rpm shaft speed. That is NOT engine speed - you need to measure your crank pulley & alternator pulley diameter to translate that into engine RPM. On a side note, Bosch's website claims they now offer "Bosch Sport Compact High-Output Alternators" with outputs up to 200A, specifically designed for people like us with current-hungry ICE and Rallye lights.

But I couldn't find a damned thing other than the press release, so I have no idea if they make a bolt-on 200A unit for our MB's.

Also: WorldPac now has the 143A and 150A alternators available. The 143A, with core (assuming you are upgrading and don't have a bad 143 to return), is ~$300. The 150A is closer to $400, which is nuts. Check with Rusty (800-741-5252, ***************) if you want a fresh rebuild. Or you can score a used one for $100-$150 if you check around enough.

Here's the photos:

HTH,

gsxr · #19 04-12-2007, 01:57 PM

Bump. I now have 150A units on my '87 and '94, and I have another 150A ready to bolt on to the '93... zero problems so far with this mod.

JimSmith · #20 05-13-2007, 10:27 AM

gsxr,

Are the links to the web sites out of date or do I have to "join" another site to see them? If this is relatively straight forward, I may do it to my wife's 1988 300E. Jim

Roncallo · #21 05-13-2007, 01:36 PM

Quote:

Originally Posted by JimSmith

gsxr,

Are the links to the web sites out of date or do I have to "join" another site to see them? If this is relatively straight forward, I may do it to my wife's 1988 300E. Jim

No all the links are almost 4 years old. Too bad, it had some interesting well thought out detail on wiring discussions.

John Roncallo

gsxr · #22 05-14-2007, 01:04 AM

Sorry about that, everyone. I changed domains and re-arranged the site a little a few years ago, which broke all of the links in my old posts. I updated everything in this thread, all the links should work now. The power blocks & distribution are different on all three of the cars I've done this on (87 blue, 87 white, 94 silver) so you can look at all of them for different ideas. I've got another 150A alternator that I'm going to put on my 'new' 1993 300D later this year (gotta finish other projects first.)

I have a 150A alternator from a 2003 (?) G55 AMG for sale if anyone wants it. It uses a different regulator than the other units I've been using - it has 2 small blade connectors instead of one small post. I'm not sure if it will work in our older cars or not - I was going to experiment but just haven't had time. If anyone wants it to play with, I'm willing to sell it pretty cheap. I have a new OE connector to plug in to the small blade terminals. This alt came from a very low-miles vehicle (under 5k, IIRC). A photo is at this link. Note that it could be modified to have TWO output terminals, which is mostly why I was interested in this type... would make installation in some setups easier.

JimSmith · #23 05-14-2007, 09:57 AM

Thanks for updating the links. Looks like you have seen every part of a W124 there is to see. Very nice quality wiring and wire routing. Jim

Hit Man X · #24 05-14-2007, 03:27 PM

I've installed the 150A into my 300SEL and the SDL, great upgrade move.

79300sdtd · #25 06-06-2007, 02:10 PM

what sort of alternator upgrades are available for the 617 engines?

gsxr · #26 06-06-2007, 06:23 PM

You can get a 100-120A unit from a VW or Saab, with V-belt pulleys, for the OM61x and M117 engines. There's separate threads about that mod... use the search feature and you should be able to locate more details. A number of people have done this to 617's. It's more work but it's possible.

gsxr · #27 01-02-2009, 12:57 PM

I just did another upgrade, this time I installed a 150A alternator into my 1993 300D (this was LONG overdue... wish I had done it sooner). For this installation, I kept the stock battery cables, battery terminals, and factory power distribution block all intact. I hadn't done this before - my previous installs used aftermarket items instead.

This method makes for an easier install (and cheaper, too). I used two 4-guage cables to simplify connection at the stock distribution block. It works perfectly. If you don't need to attach large cables to feed aftermarket stereo amplifiers, etc... I'd recommend duplicating this setup. I took extensive photos this time, and documented the creation of the custom cable. A few sample photos are shown below... the full batch of pictures are available at this URL:

http://www.w124performance.com/images/W124_stereo/alternator/