I have a stock 100 amp alternator on my 96 Blazer and want to do the big 3 upgrade.

I will be using 2 ga wire for this. I have a problem running a unfused wire from the alternator to the battery. I would like to fuse it at 90 amps. When I went to a local automotive stereo shop to obtain the fuse and holder, the rep thought that fusing it would cause me alternator rectifier issues with the stock unit.

I find this hard to believe. Electrical Guru's weigh in on this.

Thanks