4k light swithch help

[nwloves]

Got a tech question about he light switch in my 4kq.
The old switch recently went south on me and thanks to a fellow lister it
was replaced.
Now there are the same problems developing again so I took the old one apart
and found that the #30 pin has been running hot (melting things).
I run 100/80 H4's and have relayed everything (2 for the euros) including
the fogs (all of which use 10ga off the battery)
Any ideas as to the cause and source?
Thanks for any help, Tom