The blue wires are branched off the "ignition run" which IS NOT FUSED. That IGN1/ run feeds several items depending on year / model
Feeds power to ignition system
to VR
to alternator field
to electric choke if used
emissions doo dads on some years
MOST LIKELY you have a short in that blue wire or right IN the alternator. The two field connections at the alternator should show continuity between the two of them, but NOT to ground (case) of the alternator
You will be lucky if you didn't burn up "some other" wire. I would get under the dash and try to trace the "ign1" where it comes out of the bulkhead and goes to the ignition switch.
