Intermittent warning lights

[Sedanades]

My 2007 sedan has been flashing various warning lights intermittently.

Two weeks ago when there was still snow and ice where I live, the ABS/BRAKE lights stayed on after starting, and the ABS would no longer work. I drove over an ice patch to verify. Numerous key on/key off attempts didn't change anything.

The following day the ABS/BRAKE warning lights stayed off, and have remained off since.

Yesterday I noticed the Battery light remained on after starting, then went out after a couple of minutes. Today I noticed the Battery light and the Airbag light flashing on and off intermittently while driving.

Might all this be a loose plug connection somewhere, or something else? I've owned the car 2 years without any similar problems. I noticed the cover to the fuse box wasn't snapped tight, for how long I can't say.