alternator upgrade - PeachParts Mercedes-Benz Forum

fireman1073 · #1 02-21-2008, 04:29 PM

Well my stock alternator died.

Turn on the key and no warning lights then on the way back from boston my heat goes full hot and the radio dies,turn off all accesories and drive home
so i checked the regulator and the bruhes were real short.

Figured that was my problem so i cannot wait for a ordered part due to my courier job so i go to the local pick n pull and look at the saabs.

found one with the al 129x 115 amp alternator but i had no allen wrenches with me.

found the al124x 80 amp version with regular bolts holding it in so $25 later i have a 80 amp alternator.

some tips for you guys

if your getting the al129x bring allen wrenches

it comes out from the passenger side wheel well.

if your getting the 124x 80 amp it is on the upper driver side.

the 124x is a bolt in deal no changes exept running two new wires.

single blue wire from junction block on wheel well to the alt this is a keyed 12v (small wire spade connector) this wire lights the dash warning light and i think excites the alt

large alt terminal to junction block on wheel well (use large wire to handle 80 amp load) this is battery positive

i left the old alt harness in and tied it up just in case

these come from 90's saabs

that is it!

the double pulley was smaller but i used it and it seems to work fine.

sorry no pictures, dead camera

oh 84 300 sd

Steve

JHZR2 · #2 09-09-2010, 11:22 AM

So have you seen any long-term issues using the standard belts on the 124x double pulley? Getting a solid 14.4V? Belt squeal? Tightening issues?

vstech · #3 09-09-2010, 11:41 AM

it's not necessary to upgrade the wiring unless you are changing accessories in the car. did you add a large AMP? or a set of large fog lights?
if not, the 80 amp alt will only put out the 35 or so amps that the car pulls.
cheers!

JHZR2 · #4 09-09-2010, 11:45 AM

... or unless there is a high resistance connection that cleaning cannot resolve...

Actually, I wouldnt be so sure about that... Say you have a battery that is weak, nearly flat, has an internal short, etc. You could theoretically be discharging nearly 15A higher than the wiring is designed for (figure the wiring on all the cars is designed to take 65A). Not sure if 15A on that short run is a huge voltage drop issue, or a heating issue, but it still may be sound to upgrade.

Regardless the terminals need to change, so I suppose the wire might as well be replaced to a heavier gauge anyway...