My alt. had noisy bearings so figured it'd be a good time to swap in something bigger in case I ever decide to get around to upgrading the stereo. The only 130 amp Subaru I could find come in the 3.6L 6 cylinder cars.
Anyways, found one from a 2011 Tribeca with 35k miles for $75! Seemed like a great deal considering the rebuilt 85 amp is roughly the same price and this 130 amp monster is easily 3 times more expensive new or rebuilt. It needed an ear ground down to clear the adjustable bracket, and 2 high spots lowered to clear the other side of adjustable bolt block. The eyelets for the charge wire needed widening too to accommodate the larger post (10 sec job with drill bit on slow speed). The charge wire clips needed loosened to give extra slack since the charge wire bolt is in a different spot (about 2" further left). Other than that, it's a direct fit physically. The serpentine belt on the Tribeca *IS* a rib or 2 wider, but interestingly enough, after installing the factory belt it sat in the proper grooves (just an extra rib hanging out not being used). It seems to be tracking straight even at higher rpm so not going to bother with swapping the smaller ribbed pulley at this time, though a 1/4" OD difference can cause issues (like not spinning fast enough at idle to kick "ON" and actually charge), but they looked fairly similar. Also forgot to measure the pulley shaft diameter to see if they sit on the same shaft or not. This 130 amp unit, despite being very similar physically, definitely has some weight to it. Must have been a real feat squeezing all those extra windings in there Can't wait to drive at night with every single thing turned on and not so much as a dimming dash light (pet peeve)
The biggest difference is the electrical connector for the Tribeca had 3 prongs, whereas the factory alt. has 2. I checked both on wires with engine running and both saw battery voltage, though one wire is clearly a heavier gauge. SO.... I need to know a couple things:
1. I know the one wire is the "ON" source to kick the alternator charging on. What's the 2nd wire for? Heavy gauge is white, smaller gauge is black.
2. The alt has 3 prongs to connect to, any idea what's what? Can I get away with just running 1-2 wire to get it "ON"? Pretty sure I can, but I'd like to know what the 3rd wire was for? This type of alternator came out around 2010 in anything with a 3.6L. I dunno if it's physically the same as the 90 amp in the smaller engine cars.
Edited by Bushwick, 26 November 2013 - 05:59 PM.