I think this fuse only feeds the radio and nothing else....
I would remove the radio and disconnect the harnesses and try a new fuse......if it still blows, it's a wiring problem, not the radio......
If it doesn't blow, attach a grounded test light to the harness....it's connector harness C1, at terminal B1, red with a white stripe.......now move the harness around, with the test light connected, to see if the fuse blows, if it doesn't it's the radio....
If it's determined that the radio is ok, and that it is a short in the wiring, just run another wire to a power source and stick in an inline 10A fuse, cut the red/white wire a couple inches back of the harness, and attach your new power source.....that short could be anywhere.....