Key switch keeps blowing

[Sylvester]

Hi guys , just yesterday I was parked at the bank and when I went to leave I had no lights on the dash when key on ,
found out I had blown the key switch fuse (50amp) under bonnet , replaced it and it blew straight away ,
Do you have any ideas on where to start ,sparkys away till wednesday , The car is dry as , clear day , no puddles were gone through,
the only isuse is under the bonnet is pretty oily with some minor leaks I haven't cleaned in ages .

Thanks in advance
steve

[Sylvester]

Ok solved it , my starter motor was causing it , so new starter and she,s all good.