I wonder if it is a ground problem. since it attaches to the engine block- I would check to make sure all the ground straps to the engine are good. (not loose, missing, corroded).
Theres a post around here (traverse/acadia/Enclave forums) where engine grounds are listed.
I recently rebuilt the front end of my traverse and now it's drawing too much from the battery. Ive heard the grounds are notorious for corroding, but I can't find any information on where the grounds are located. I'm about to start testing circuits to find the draw. But I dont know where to...
Best to go to a shop that specialized in auto electrics repair. Good to know what is failing in the alternators, a winding of the armature or a diode or bearing assembly. If it is the diode a shop should be able to determine what is generating the problem with the alternators. It is insane to keep installing alternators and hoping that something will magically change.
The shop that replaced all those alternators should have tested each time before replacing that high dollar part. Your battery seems to be fine and your main components seem to be fine and since there are no changed accessories, I would go back and do another visual and re-tighten the connections. If you knew the voltages and amps, you could check the input and outputs. You could disconnect the battery and check resistance through the alternator as well. I don't know where to find such a schematic ...maybe someone here has that information. As Montereyjack2$ suggest, got to a auto electrical shop.
Charging circuit. The problem is that you don't know what the BCM and ECM are telling the alternator to do via the CAN bus (the dotted lines coming out of the box with the up/down arrows). Just a thought: Maybe the Battery Current Sensor has failed (or is no longer hooked up?) and so the BCM/ECM, not seeing any current flow, are telling the alternator to put out power like mad and it's burning out the diodes in the alternator???