I am trying to diagnose a problem at distance. 1990 745 non turbo
Car died for no apparent reason. Battery was discharged and has since been charged and tested OK and is back on the car. Car cranks fine at present. Dare not drive anywhere.

The battery idiot light on the car did not come on while driving and does not come on at all when you turn the key. Check engine comes on, oil light comes on, battery symbol light does not come on.

Apart from the possibility that the idiot light bulb is broken, what other reasons could explain that light not coming on when the ignition is turned on and the car is not running?

I am guessing that either the alternator is bad or that the battery connection is bad on the wire that goes to the alternator from the battery. At this point I do not know for sure if the alternator is charging the battery or not. Without a functional idiot light I can only guess.
The family member is riding a bicycle to Walmart to buy a voltmeter.

Are the factory battery terminal + connections usually with three cables all crimped together in one clamp?

Any help or knowledge about this would be greatly appreciated. Car is in Wilmington NC and I am 200 miles away.

Thanks, Steve