as above on my m8's 2w/d Cossie

already had the fuse box done(melted)so rewired it direct from the battery with a 30amp fuse inline all good for about 2 weeks or so then the fans either come on constantly even when parked for the night (stone cold engine) or NOT at all. all the switches look burnt around one of the terminals.
he's spent £50 on switches over the last 3mths

any ideas welcome