Oldsmobile - Bravada :: 1997 Intermittent Stalls And Voltage Found To Drop To 0

1997 Olds. Bravada. 4.3L original engine. 217000 miles, maintained well (routine oil changes, fluid checks, etc)

Intermittent stalls. When stalling, voltage found to drop to 0 even though radio, headlights, and dash lights remain functional. Engine will sometimes "automatically" return to running (it doesn't turn over, just runs) and the air bag light flashes, other times it needs to be restarted. No problem restarting, but may or may not stall a few seconds later. No specific action triggers the events. On a potential side note, the rear wiper motor will spontaneously start running occasionally (once per week frequency typical).

Attempted fix: cleaned both battery contacts, removed and cleaned frame ground, removed and cleaned body ground, all done with either sand paper and/or a wire brush