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Thread title corrected.
There is a fusible link at the starter, connected to the main B+ stud. This circuit powers part of the ignition switch. An indication of failure of this link or that part of the ignition switch would be that the warning indicator lamps to not illuminate when the ignition switch is turned to the CRANK position, as they should normally do.
There is another fusible link near the battery positive (B+) terminal which connects to the alternator and some other power circuits. There are several other fusible links near the battery main power junction block. If any of those have failed various circuits will not have power. Before replacing a failed link it is imperative to determine the reason for its failure.