Some alternators are rated to 130 amps - they don't make fuses that size except for fusible links. Also to be considered is that the power that the alternator provides goes thru more than one cable - in the case of the Commodore, the white cable supplies power directly to the operational side of the car (thru a fusible link) whilst the thick red one supplies power to the battery (to replace power that has been drained previously and with no fusible link). It is a balancing act and one which the manufacturer has spent a bit of time and $$$ on. Lesson over.