So where is the main fuse if it isn't under the seat and isn't in the fuse box? It's in its own special place under the bike's right side cover. Here's how to locate it.
1. Remove the bike's right side cover
2. Remove the coolant tank (no need to remove the hoses if you don't want to, just pull the tank away from the bike. On the other hand if the tank is full of grunge you might want to take the opportunity to remove and clean it up.
3. Now look for four box shaped electrical gizmos. Those are all relays that provide high amperage power to your headlight, starter and other items. Locate the starter relay, furthest to the left.
4. The master fuse is under the red cap on top of that relay. Depress the side latches to remove the cap. It's held in place not only by the latches but there are four electrical connections plugged into the top of the relay. If any of those posts is corroded it could make removal a little dicey. Just wiggle the cap up, don't pry it up by sticking metallic objects underneath (is explanation really necessary?
5. Replace the main fuse with your spare but 'only' after repairing whatever short caused the fuse to blow in the first place. If the electrical posts are corroded clean them up and apply di-electric grease available at any auto supply store in tube or pressurized can form. Di-electric grease provides corrosion protection but allows full power to flow through contacts.