Fried headlight wires!

[gsxdan]

So I picked up a used 05 750 gsxr last week. When I was riding home in the dark i noticed the lowbeam was dropping in and out.
Got home and poped out the instrument cluster and I was greeted with a toasted H4 connector.
Any ideas on what would cause the plug to burn out? Looks like its on the neg side of the globe

 

[Lataanvain]

Bad/corroded contact lead to voltage rising and in the end melting the connector.