1995 Oldsmobile Aurora OBD display

When I started my car and attempted to lower the passenger window it seemed stuck. I attempted to lower the window a few more times and the display on the OBD read: "Check Charging System". Now, is this an alternator problem? I have had most, if not all, the original parts replaced except the alternator. The car has 100,050 miles on it.

The OBD would show a reduction in voltage ranging from the initial, sat overnight, next day turned it on setting of 15.4V. When needed to turn headlights on, e.G. Construction zones, it would drop down to 14.9V. If the lights were on for prolonged time e.G. Waiting in traffic in a construction zone, it vary between 14.7, 14.8-14.9V.

If the engine has been on for prolonged time, going through construction zones, the OBD would read a falling Voltage e.G. 14.7, 8 down to 13.0V incrementally in tenths of a Volt. The engine "appeared" to run normally and the power systems "seemed" to function normally.

So, not being electrically inclined, I do not know what the problem is.