The Legendary " Saab " Alternator Upgrade

[BenzDieselTuner]

been hearing about this for over ten years now, never have gotten a straight answer on it much past some part numbers.....well now i have one, "brand new" and it's sweet, the lights have never been brighter.....

http://www.ebay.com/itm/131061729708?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

the seller, Eagle Auto Electric, is a "real person", as in, this is a real reman business in california that takes pride in their work, this isnt sloppily thrown together by some mexican factory slaves LOL......it came all packed tightly, the paint still smelled fresh......he gets them and redoes them and includes even connectors for hooking it up, as one cuts and removes the plug, and runs an additional 4-guage wire to the positive post of the battery......my lights on the car have never been so bright, not so much as the slightest voltage drop even under full load everything turned on full blast......he even threw in a free pulley for me, as mine had a bunch of banged up fan fins from when the tensioner broke one time......

anyways, i am so stoked about my abundance of power onboard now, that i just had to share with you all.......these bolt on to pretty much any old Benz, and is a very good upgrade, i recommend everyone get one ASAP

[compu_85]

Your link seems to be broken

-J

[ichris93]

Originally Posted by compu_85

Your link seems to be broken

-J

Try this one Mercedes Alternator Diesel 240D 300D 1974 77 78 79 80 81 82 High Amp Generator | eBay

[Smoker]

I did this upgrade last week. The alternator can be gotten from saab 9000's in the picnpul or you can buy a reman at your favorite parts place for $80 - $120 depending on your choice.

It's a Bosch AL129X. I used the one out of one of my many Saab 9000 parts cars littering the back field here.

[Phil_F_NM]

Which harness does this hook up to? W123?
I think I'll need to do a complete rewire to upgrade the alternator in my 1972 220D. There's no way I can have everything running (heater, headlights, fog lamps, stereo) right now with the 35A stock unit. Even upgrading to the W123 55A unit would be great.

Phil Forrest

[Smoker]

It doesn't hook directly to the W123 harness. Our harness has 3 spade connections, the AL129X only has two posts.

There are threads on how to, but basics: The thin (in my case blue) wire goes to the smaller post. Two new heavy gauge wires are made up and both go on the large post. You can choose to then run them to the stock junction box where battery and starter both have a lead, or you can run one to battery and one to starter directly.

Don't cut off the old plug, just put some nice electrical 'lube' on the contacts and tape it over, zip tie it out of the way for when you want to go back to stock....ya know for when these are worth a fortune .

[OM617YOTA]

Good stuff. Robust electrical power is SO relieving after making do with a mediocre alternator.

I swapped in a Delco 22SI semi truck alternator. 150 amps continuous duty, 80 amps at idle. I can maintain charging voltage with everything turned on, including the glow plugs.

[funola]

Originally Posted by Smoker

It doesn't hook directly to the W123 harness. Our harness has 3 spade connections, the AL129X only has two posts.

There are threads on how to, but basics: The thin (in my case blue) wire goes to the smaller post. Two new heavy gauge wires are made up and both go on the large post. You can choose to then run them to the stock junction box where battery and starter both have a lead, or you can run one to battery and one to starter directly.

Don't cut off the old plug, just put some nice electrical 'lube' on the contacts and tape it over, zip tie it out of the way for when you want to go back to stock....ya know for when these are worth a fortune .

Good idea not cutting the connector/ harness. I bought the Eagle elec 120 alternator for the 83 300D (sold) and did cut. Not going to make the same mistake if I ever upgrade the alternator on the 85 300D.

[BillGrissom]

I might consider the 120A alternator if I needed to change mine alternator anyway, especially since cheaper than the $150 I paid in 2001 for a NAPA one. I like the stud outputs, which is more reliable than the spade connector on my 85 300D, plus no sense having 2 output spades & wires like the factory design. Otherwise, my battery recharges fine w/ the factory 65 A alternator, so I don't see the necessity.

The headlights should work fine off the battery alone. If too dim, there are probably issues with corroded connectors. I don't see a need to keep up with the glow-plugs while cranking. Indeed, that is silly. A larger alternator would just load the starter motor more while cranking, causing more draw from the battery. It isn't a "perpetual motion" machine. On the same thread, why run the alternator output to the starter? Indeed, it would be nice to disable the alternator while cranking, which I think some car systems do. If your present alternator keeps the battery charged, a bigger one would just risk smoking wires.

[compu_85]

I find the 110A alt I put on my SDL does fine.

Remember that larger alternators put more stress on the crank pulley and belt drives - they have more mass.

My Jetta has a 120A alternator (to power all 7 glow plugs when the car is cold), and the Passat has a 180A (!) (to power the 1200 watt electric cabin heater, glow plugs, DEF heater, etc)

-J

[Smoker]

Originally Posted by BillGrissom

I might consider the 120A alternator if I needed to change mine alternator anyway, especially since cheaper than the $150 I paid in 2001 for a NAPA one. I like the stud outputs, which is more reliable than the spade connector on my 85 300D, plus no sense having 2 output spades & wires like the factory design. Otherwise, my battery recharges fine w/ the factory 65 A alternator, so I don't see the necessity.

The headlights should work fine off the battery alone. If too dim, there are probably issues with corroded connectors. I don't see a need to keep up with the glow-plugs while cranking. Indeed, that is silly. A larger alternator would just load the starter motor more while cranking, causing more draw from the battery. It isn't a "perpetual motion" machine. On the same thread, why run the alternator output to the starter? Indeed, it would be nice to disable the alternator while cranking, which I think some car systems do. If your present alternator keeps the battery charged, a bigger one would just risk smoking wires.

I simply followed the stock wiring, with heavier gauge wire. I don't know the 'why' of the original wiring scheme....that is, output to both starter and battery, but they flow to the same place anyway.

[BenzDieselTuner]

Originally Posted by compu_85

Your link seems to be broken

-J

sorry, i never tested the link, i edited the original post, that link now works as well

[BenzDieselTuner]

when i wired it up, i followed the man's recommendation, and the factory harness's two heavy-er (tiny little guys) wires are connected via ring connectors to the large alternator post, the tiny start-charge wire goes with a ring connector on the little post, bolt it down, and the large post has a new 4 foot 4 guage battery cable on last, with a little washer and the copper nut.......new heavy cable runs directly to the battery positive post, ensuring an excellent and quite upgraded connection over the tiny weak wires running through the factory harness, which are also still used....

i'll say it again, what i love about this is part that a "real someone" actually rebuilt it, sandblasted the casing like new, painted it perfectly, etc, i was postively surprised the moment i opened the box, at the obvious pride the person doing it took in their work, how carefully packed with "homemade" custom packing materials, the neat little idiot-proof instruction ribbons attached to each post that he printed up and attached to the posts with the new connectors......i'll trust this to go FAR beyond it's 1 year warranty, way before i ever would a cheap mexico reman from some advance auto somewhere......

[BenzDieselTuner]

Originally Posted by OM617YOTA

Good stuff. Robust electrical power is SO relieving after making do with a mediocre alternator.

YES !!

[charmalu]

Here is the old AL-129-X 115amp Alternator thread, all your answers and questions are answered and sorted out here.

http://www.peachparts.com/shopforum/diesel-discussion/93569-alternator-115-amp-bosch-al129x-works-123s.html


Charlie