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
“When stalling, voltage found to drop to 0”
The voltage of what drops to zero measured where/how? Its just obvious that the actual voltage flowing around isn’t at zero since you still have a bunch of things running. So where are you getting that from?
Do you have a check engine light?
Lots of corrosion can be hiding underneath of the insulation on those cables. You might peel off some insulation to get a look underneath. Anything but clean, shiny copper is a problem.
I’d also expand my attention in terms of power connections. There are generally multiple grounding points all over the car. The relevant ones will probably be under the hood. Cleaning the mains is obviously good, but there are others. You also want to worry about the power connection to the main power center junction box under the hood. Follow the + cable from the battery & alternator and clean up every connection you find.