"Alternator" 115 Amp Bosch AL129X works in 123s! - Page 4 - PeachParts Mercedes-Benz Forum

#46 06-10-2005, 02:54 AM

Installed this alternator in my 300SD (w126) and I am loving it. No more dimming headlights when turning on the AC, etc. (I have aftermarket headlamps).

The instal was nice and easy and I even threw a rebuild in the works before installing the alternator. System seems to be a lot happier.

t walgamuth · #47 06-10-2005, 06:23 AM

heck i thought i was living high upgrading my 240 from 45a to 65.

Ramblin · #48 06-10-2005, 06:29 AM

After reading this thread I ordered this alternator and installed it with very little trouble to solve an obvious problem regarding the stereo install I had planned. I finally finished the stereo install (see 123 Install in Car Audio) and even with the system cranked up full I get no headlight dimming. I am running 4 six channel amps all bridged for 12x110 watts RMS. Thanks to all those that contribute to this forum.

t walgamuth · #49 06-10-2005, 06:31 AM

with a sound system that powerful i would be concerned about the welds in the unibody coming loose.... not to mention ear damage.

#50 08-16-2005, 04:37 PM

My alternator is full-fielding all the time now.

I want to replace it with a better unit. I know the 115A will work but will the more common 80A unit also work?

Brian Carlton · #51 08-16-2005, 06:14 PM

Quote:

Originally Posted by t walgamuth

with a sound system that powerful i would be concerned about the welds in the unibody coming loose....

.....................

dieseldiehard · #52 08-16-2005, 06:44 PM

Quote:

Originally Posted by 82-300td

My alternator is full-fielding all the time now.

I want to replace it with a better unit. I know the 115A will work but will the more common 80A unit also work?

Yes, there is an 80A Bosch unit type AL69X that works fine.
You may have to change the pulley from a single to a dual or the other way around, to suit whatever is on your engine, and you need to run a larger wire (or parallel two 10 ga wires) to the alternator for the alternator output if you want to keep voltage drop down.
And you need to convert from a plug-in connector to individual wires that terminate in lugs. That shouldn't be hard for anyone experienced with electrical work.

dieseldiehard · #53 08-16-2005, 06:52 PM

Quote:

Originally Posted by dieseldiehard

Yes, there is an 80A Bosch unit type AL69X that works fine.
You may have to change the pulley from a single to a dual or the other way around, to suit whatever is on your engine, and you need to run a larger wire (or parallel two 10 ga wires) to the alternator for the alternator output if you want to keep voltage drop down.
And you need to convert from a plug-in connector to individual wires that terminate in lugs. That shouldn't be hard for anyone experienced with electrical work.

SAAB uses the identical AL69X as does Mercedes V8's like this on eBay:

http://cgi.ebay.com/ebaymotors/Saab-9000-Bosch-Alternator_W0QQcmdZViewItemQQcategoryZ33573QQitemZ7993393398QQrdZ1

#54 08-16-2005, 08:56 PM

The 115Amp unit works great and you get system idle voltage floats around 14.2volts. When you rev it up the voltage does not change at all (since its already just loafing along).

With EVER ACCESSORY on, the system drops down to about 13.1-13.4 at idle (AC, High Beams, Radio, Fan, etc.)

The w126 body uses a dual row belt on the engine and after I swapped over the pulley, put in new bearings, and brushes; the 115Amp works great.

Installation was not too hard though you have to do some tricky buisness to get the case to clear the mounting stuff.

Keep an eye on your battery if you do this upgrade as the higher voltage at all times likes to boil the battery if it gets hot out

80Amps would be good however as far as aftermarket stereo goes, I think 80amp would still be pushing it. 80amp is what these cars SHOULD have had on them out of the factory

BTW I kept the stock wiring, offed the connector on the end, and just added two ring terminals. The stock wiring is PLENTY beefy on a w126 body to handle the 115amps. I think its dual 10 or 12awg. over to the junction point.

#55 08-16-2005, 11:42 PM

How does the saab wiring go? Just one ground wire and one + output wire?

#56 08-17-2005, 01:12 AM

Quote:

Originally Posted by 82-300td

How does the saab wiring go? Just one ground wire and one + output wire?

Same as the stock except the alternator on the stock has "2" output spades...(both the same...just 2 to handle the current)

The Bosch AL129X has a field and power wire just like any other alternator.
The field is a spade connector, the power is a stud, the ground is through the case

Californian · #57 08-17-2005, 01:35 AM

I thought I read somewhere, on this forum, there were a post about using a Ford Voltage regulator and modify it somehow to get the alternator to deliver higher voltage and higher amperage.

#58 08-17-2005, 01:52 AM

Quote:

Originally Posted by Californian

I thought I read somewhere, on this forum, there were a post about using a Ford Voltage regulator and modify it somehow to get the alternator to deliver higher voltage and higher amperage.

Sucking more power out of an alternator than it is designed for is rather risky...it just overloads a lot of parts.

You can get adjustable regulators for most alternators however if you want to have good solid power and no problems (and want your brushes to last more than 15min) you should go with a unit designed for its rated amperage

Californian · #59 08-17-2005, 02:07 AM

:-)

I found this link:

http://members.1stconnect.com/anozira/SiteTops/energy/Alternator/alternator.htm

Californian · #60 08-17-2005, 03:28 AM

Does it mean if I replaced the diodes inside the Alternator with better spec diodes, and a higher output voltage regulator, I get more output power ?

My W140 has an alternator with this part number 009 154 3002 80 . I wouls assume this is either an 80A or a 90A alternator. Could someone confirm this ?
Also, would something like this fit on my car ?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=7987197013