I take it that you have the actual handbook? If so, it should list which fuse relates to which circuit. Failing that, could you not just check the actual fuses fitted in the car to see which one (if any) has blown? If you cannot see which fuse has blown, you could try replacing each fuse one at a time, with a known good fuse until the horn etc works. If none of this works, then it may be a connector somewhere after the steering wheel.