Main fuse blown......

Hi,

Thanks for any help; I've done a quick search and couldn't find anything. Nor in the handbook or Hayn*s manual.

300tdi DEF;

While on holiday, I tried to start her after a stop, no ignition lights-totally dead, side lights yes, turns out the 60amp service fuse had blown, replaced with an 80amp I got hold off, that blew a few days later, now replaced with another one.

There's obviously a short or problem somewhere; any ideas? Or is it just a case of testing everything?

Thanks again for any help.