97 GMC Yukon WONT START

Squeaking belts won't have anything to do with starting. Also, I'm confused as to which system you're referring to. The ignition system is not the starting system. There's an ignition fuse and relay, and there's a starting relay. No starting fuse.

Whenever a fuse blows, it means there's too much current being drawn through that circuit. What causes too much current draw is high resistance, a short in the wiring or a faulty part (which usually cause one of the two first issues, just internally).

You'll need a voltmeter to check all of the wiring in which ever circuit is causing you problems. This will include all positive cables/connectors/terminals. Also look for corrosion and faulty insulation on wires.