the biggest problem is the fuses and relays go a bit manky on the terminals which causes a resistance between the fuse/relay and the fuse box which in turn genarates heat, melting the fuse/relay etc.
the best way to conunteract the problem is make sure all the fuses,relays and fuse box have clean and shiny contacts and use electrical grease or vasiline to stop them corroding again.
done this with mine and not had no problems since

P.s. take every thing out one at a time so you know where they go back.