Post engine swap fusible link issues

[grayguy]

Ok, this past weekend I swapped a 97' 2.5 into my 97' L. So 2.2 out and 2.5 in. For some reason it is constantly blowing the fusible link. I have figured out through trial and error that it blows only when I plug the harness into the alternator. If I leave the alternator plug in disconnected it runs great and doesn't blow, as soon as it's
Plugged in it pops. At first I figured the alternator was messed up, but I swapped it for another and it still does it. I also swapped out all the relays in the fuse box on another hint I got, but that had no affect either. Anyone have any ideas?

[Huffer]

You have to be grounding out somewhere along that harness then - when the alternator is plugged in, it must be grounding to something and popping the fusible link.

[grayguy]

Well I still can't figure this out. I tried a third alternator, that had no affect so it's a wiring issue for sure.

I played with the voltmeter, and with the alt unplugged, I'm getting the same volts on the battery as the alternator harness, so it's not giving the regulator the wring reading and causing it to over charge.

When I plug in the alt, the fuse blows, but the alt says it's putting out 13.8-14.2 volts ( car runs after the link is blown for some reason?)

The weird thing to me is that after the fuse blows, I'm still reading like 11.5v(or what ever the battery is at) on the fused side of the link....is that normal?

[racingking951]

This same thing has happened to me too. For me it happened when while I was driving home one day and the wire on top of the alternator (the charge wire iirc) came separated from the stud on the alternator. The wire hit the intake manifold and blew the fusible link. I ended up replacing the whole wire with some 8gauge wire I had laying around because I couldnt find the short. So for me it was just a little 2ft wire that caused the problem.

[grayguy]

Well, I don't know the science behind it, but I replaced the fusebox and the problem seems to be completely gone. This is the 2nd Subaru I've had to replace the fusebox in...which leads me to believe that I am cursed.

[grayguy]

New development: it still blows after a night of rain.., :(

[racingking951]

You must have some exposed wire somewhere. IIRC that fusible link has a direct line to the alternator that must be getting grounded out. Last time I had a wiring problem it took me hours fine the problem so good luck. It should be a melted wire or a wire that has been getting rubbed against body or engine