Now listen to this.
It was a faulty fuse that caused a) horn to sound scrambled b) turn signals not to work and flasher to sound short circuited c) starter electric motor not to work!
On top of everything, it was neither horn or turn signals fuse! The fuse was glass-type (not cartridge one).
Changed the fuse and everything is back to normal.
Crazy s*it, that electric system, isn`t it?
p.s. At least, the cost to fix it was close to zero!