I suspect the wiring loom is chaffed through and shorting out on the frame somewhere. I'd start by looking at the left hand side where the loom passes tight to the frame as it goes forward to the clocks.

Rather than keep throwing fuses in, make up a light bulb with a couple of short wires to put into that fuse holder, that way you'll know you've found the fault when the light goes out.
_________________
MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball