AL129x Bosch Reman Alts available for $100!! Fits 126 as a drop-in! - PeachParts Mercedes-Benz Forum

deerefanatic · #1 10-31-2006, 08:22 PM

Alright Guys,

The name of the place is California Alternator & Starter. Their phone number is 1-310-530-6410 and their Ebay user ID is "roomik70" .

I got my AL129x in about 3 days, it is as you can see in the pics a nice beefy and VERY clean unit. It had a new Bosch brand voltage regulator. New bearings were also obviously used as the shaft had that slightly stiff feel to it yet. All in all, a very grand rebuild, with a 1-YEAR, UNLIMITED MILEAGE WARRANTY!!

Now, for the nitty gritty:

I used 4 Guage cable and gold plated crimp-on lugs for the wire (same as the wire coming from my new battery cables......) and made a new wire to goto the exciting stud. I had a problem with this unit, as with my old Alt (ever since putting a Bosch VR on it) that it wouldn't excite and turn off the dash lamp until I revved the engine just slightly. The tech at California Alt & Starter said this is due to the fact that the new Bosch VR's require more current to excite at Idle than did the old VR's. His recommendation was to put a 35-40 ohm, 5watt resistor in Parallel to the dash lamp, effectively doubling the current to the stator, while not require a larger light bulb. The dash light will still work in this case.

I had problems though, with my new alternator only putting out 13.7 volts maximum with now load. With load, it would run 13.0-13.4, and would fluctuate up and down in that range. Fully loaded with everything (rear defroster, fan on hi, Hi beams and driving lights, radio, etc) it would run about 13.2 most of the time and drop to 12.0 at a stop-sign idle.

I decided to ditch the Bosch VR and put the aftermarket that had been in my 55 amp in the alternator. Voltage now runs about 14.2 at idle with nothing drawing. With everything loaded and engine at a stop-sign idle (idleing in gear while stopped) it will still drop to the 12.0 volt range (650 rpm idle) but just tapping accelerator up to 1000 rpm gives normal voltage... Running down the road fully loaded it varies between 13.5 and 14.0 volts. Also, with this voltage regulator, the alt excites right away and doesn't require and additional resistor in the exciting circuit, nor does it require the engine to be revved. It "just works".

All in all, I am very pleased. Using a giant ammeter I have, I measured with everything running and a fairly low battery, the alternator was pumping 85 amps and still maintaining 13.4 volts at 1000 rpm engine speed (throttle blocked slightly open while in park......)

Oh, ya, when pumping 85 amps for an extended period, the alternator gets uncomfortably warm, so watch where you stick those hands when experimenting!

As of when I got mine, these folks had 4 more for $100 (includes FREE shipping) and could probably get more if the demand was there for it...... They were quite intrigued with how easily they could be implemented into the Mercedes Enviroment.

As a final note, the $100 price doesn't include the pulley, I reused my old one as stock pulley would be for a serpentine belt anyway.

deerefanatic · #2 10-31-2006, 09:54 PM

Also, some new battery cables and clamps would be in order, something like this previous post of mine:

"Hi all I am putting new battery cables on the Benz in preparation for winter. I figured that those tired old 25 year old battery cables won't do justice to my new Grp49 battery.

I have competition solid brass battery clamps with platinum finish. I have 4 Gauge cables going to Chasis Ground and to the Power Distribution terminal on the passenger fender where alternator and fusebox wires terminate. Then I have a 1/0 Gauge cable running to starter mounting bolt on engine and a 1/0 Gauge going straight to starter Soleniod. Also, my 8 Gauge wire going throught the firewall for my inverter and car amp are terminated in these clamps too!

Deffinately worth-while if you're going to harness that extra current or live in the North (the home of hard starts......)

Here are some pics of my cables....

deerefanatic · #3 10-31-2006, 09:56 PM

And some more pics..........

SD Blue · #4 11-01-2006, 09:48 AM

Matt,

Where did you aquire the cables, and even rarer, the terminal ends. I thought about replacing some of my cables, because they were starting to look a little haggard, but put the task on hold because it was just taking too much time to find a source for the parts.

deerefanatic · #5 11-01-2006, 09:59 AM

Parts Express www.partsexpress.com

My set up cost me around $75 for the stuff I had, but I could have easily spent over $200 if I'd went for premium everything (overkill I think.........)

I can list the part nums if necessary......

asnowsquall · #6 01-11-2007, 09:23 PM

Now I just need to figure out how to wire it up.
Whats what here, the big lug is + and the small - ??

Did you just get rid of the original connection?

Thanks,
Dave

vstech · #7 01-11-2007, 09:54 PM

Quote:

Originally Posted by asnowsquall

Now I just need to figure out how to wire it up.
Whats what here, the big lug is + and the small - ??

Did you just get rid of the original connection?

Thanks,
Dave

go here...
"Alternator" 115 Amp Bosch AL129X works in 123s!
or here...
http://www.peachparts.com/shopforum/diesel-discussion/93569-alternator-115-amp-bosch-al129x-works-123s-post1252171.html#post1252171

Monomer · #8 01-11-2007, 10:04 PM

Minus (-) is just a ground.

It dosnt need to be as think as the Positive (+) because it's not carrying dc current (or; not a lot of it)

vstech · #9 01-11-2007, 10:23 PM

Quote:

Originally Posted by Monomer

Minus (-) is just a ground.

It dosnt need to be as think as the Positive (+) because it's not carrying dc current (or; not a lot of it)

are you sure about this being where the post gets connected? I did not know, so I posted links to another thread that goes into great detail on the upgrade.
John

SD Blue · #10 01-12-2007, 12:34 PM

Grounding needs to be just as big as the Positive side. On every alternator I've seen, this is done through the chassis of the alternator to the block.

On the old alternator, You have these connections:
(2) B+ wires that connect to the same location on the terminal strip
(1) D+ wire that connects internally to field and externally to the charge indicator.

The new alternator should connect nearly identical. (I'm thinking that both studs connect to the terminal strip)......I used to have a link to an electrical rebuild place. I'll see if I can find it and repost.