2002 Perodua Kelisa wiring/electrical fault, abs stop light on, horn not working.

Abs stop light on constant, horn doesnt work. Mechanic did diagnostic and says wiring fault is blowing fuse, he bypassed the fuse to show both issues resolved. Need to locate the wire fault thats causing the problem. Can wiring fault be found without diagnostic tester? Can somebody please point me in right direction?!