New 75amp alternator..blew fusible link.

It looks like they tapped power for the ECU off the resistor, this is correct (without looking at my book) but usually it's done a little more discretely. Correct me if I'm wrong guys.

As for the fusible link problem. I think your going to have a number of problems because it looks like your still running the mechanical regulator and your stock one wasn't designed for the 75 amps and your running too much juice throught the alt gauge. I would replace the regulator with a later electronic, replace the fusible link (NAPA has them) and make sure all your grounds are good. The e-reg will also be a little better for the ecu, the box likes a steady voltage a lot better than the flicker of the black box.

I have seen a number of dash fires cause from burning up the alt gauge in the dash so definitely don't bypass the link.

Good luck!