intermittent start problems

latest sequence:
opened/shut door -> int lights come on normally, shut off after 30sec
turn ignition on:
-> only faint oil light lit on dash, then faded

tried ignition 2nd time:
-> full dash lights, but only click -> no starter & then dash lights go dark.

Opened door,
30sec buzzing & little orange light near parking brake, everything else dark...

Any help on what to check next? Possible replacement(s)?

 

followup: was a bad negative ground connection...