Odd electrical gremlin. no start, dim dome light (some times) buzzer comes on and off

Just now, I went out to work on it. Initially, the buzzer wouldn't come on and the dome light was dim. I checked the bulkhead connectors, wiggled the connections at the relay, checked the battery terminals etc. Still nothing.

Could be just battery connections. Very first thing I told you, did you do that?

He says he did.