2011 Chevy traverse

2011 Chevy traverse keeps blowing the ECM 1 fuse whenever the car hits 2500 rpm that’s driving or sitting in park. Now I think I’ve got this figured out just by luck I noticed the alternator was whining pretty loud so I decided to unplug the 2 wire connector. Revved it up fuse didn’t blow plugged it back in revved it up fuse blows. I did this several times and went though a handful of 15 amp fuses enough to say ok this is definitely the problem. Now my question is how do I actually diagnose this? What could I do to prove this is the problem if I hadn’t got lucky by unplugging that? I’ve been looking through prodemands wiring diagrams and it’s not making sense to me. If I can get some tips or anything it would be greatly appreciated thank you.

just check the wiring integrity circuit isolated no b+ wires touching ground throw on an alt and see what happens

Give yourself more credit, you noticed a symptom that could be related and came up with a test on the fly to prove it. Job well done in my eyes!

Like you probably saw on the wiring diagrams, the two wire connector you unplugged doesn't actually have any load circuits in it. It's just Gen-F for the feedback circuit, and Gen-L for the field command. They're just pulse width/frequency signals.

At a guess, I'd say unplugging the alternator has more to do with changing the charging system output than it does with those two specific circuits.

Now my question is how do I actually diagnose this? What could I do to prove this is the problem if I hadn’t got lucky by unplugging that?

I think I'd start with monitoring charging system voltage at idle with the alternator howling, as well as the Gen-F and Gen-L PIDs. Continue monitoring as you slowly raise the engine speed up. If there really is something wrong with the alternator, then I figure you'll see something wrong in the charging system output.