How to check the fuses
Your fuse box, or "Junction Box" as the manual calls it, is behind the right side seat cowl. Remove the seat first, and then the plastics on the right side of the bike. You should see a box that says "Fuse" on it.
Remove the cover. It comes off really easily with hand pressure. You'll see the fuses, along with a couple spares. The 30 amp main fuse is found in the starter solenoid unit next to the fuse box.
Use a test light to check them. It's fast and easy. However, you may be able to find a blown fuse by a visual inspection. Take out the fuse and hold it up. The metal fuse part that's inside the plastic comes in a variety of shapes, but they're all similar. You should be able to see a break in the metal. A good fuse will have a continuous piece of wire running through it. This picture shows a broken, or blown, fuse.
For more certain results, use a test light. Okay, if you don't own an automotive test light, go buy one at any auto parts store. They look kind of like a pointy screwdriver with a wire coming out of the end. One should set you back about five bucks.
This is faster, safer and more reliable than visual inspection. You can do the whole bike in well under a minute and make no errors.
Oh: There are a couple of spare fuses in there. Obviously, they don't need to light.
Which fuses go to what
The following is a list of what is covered by each fuse. This is for a 2006 bike; yours should be similar, if not identical. For more detail, consult the EX250 Wiring Schematic.
Fuse No. 1 (10A) provides +12vdc via an Orange/Green conductor to: Turn Signal Relay (Flasher Unit)
Fuse No. 2 (10A) provides +12vdc via a Brown/White conductor to: Horn
Fuse No. 3 (10A) Provides +12vdc via a Brown/Blue conductor to:
Fuse No. 4 (10A) provides +12vdc via a Red/Blue conductor to:
Fuse No. 5 (10A) provides +12vdc via a Blue/Yellow conductor to: Headlight Relay (Terminal 30)
Fuse No. 6 (10A) provides +12vdc via a White/Black conductor to: Auxiliary Leads - Rear and front
Fuse No. 7 (10A) provides +12vdc via a White/Blue conductor to: Cooling Fan Switch