Forget about the schematics, for now. Put your eyes and hands on the fuses - obviousy check them, but pull them out and check for cean contacts, both the fuse and the receptacle. Check for clean contacts on ALL wires (ppos and neg) at the fuse panel and the switches. This means, not just "look at", but remove and inspect. Look for broken wires at the spade, too. You also need to look at the bow eye bulb, itself... along with the wires/connections up there. You can test the switch with an ohm meter or even jump the switch to directly power the light. Owner's manuals don't always have a true schematic but they have wire color coding, based on use - you can use that to figure things out easily enough.