Drains power and shuts off while in motion, new battery and alt

The battery itself may have an issue? You could try disconnecting the cable when you park and see if something is truly draining the battery. If it is you may notice a slight spark when you disconnect the cable. The alt may have a bad diode so it will charge the battery but drain it once the motor is shut off? Or it could be something like you suggested. The radio remembers its settings by being connected all the time. However a stock radio does not take much from the battery.

Check for a blown fuse, if I remember right Oldsmobile had a charging fuse in those years.

unhook hot wire to alt at night if batt is up the next morning it is the alt

The alternator may charge fine but could drain the battery through a bad diode,have you checked the alt for a bad diode?Disconnect the battery positive cable.Put a regular 12v test light between the battery positive post and the positive battery cable.If the test light is bright you do have a drain,if dim it is OK.A dim light may mean the drain is internal in the battery.If you do have a bright light remove a fuse ,one at a time from the fuse box until the light goes dim.Once dim you have identified the bad circuit.If removing all fuses do not dim the light,disconnect the alt charging wire at the alt,if that dims the light,then you do have a bad diode.DO NOT create a drain(bright light) when checking for the drain by turning on the key or opening a door/trunk etc.
Also,do an overnight battery check by disconnecting the battery overnight,if things are fine the next morning after the battery was disconnected then it is a drain in the vehicle,if the battery is dead even after being disconnected overnight,,then the battery is bad.

Your alternator cant be good if all those dash lights are on then the alternator is bad, reoplace it and make sure the battery is tested, a bad battery can and will destroy a new alternator, also make sure the connections at the rear of the alternator are good, the reason for car dieing in motion is due to the battery draining down and theres not enough voltage to keep ecletrical components going, you must have a bad connection at alternator or alternator is bad. and the last thing to check would be the alt fuse which should be located near the postive battery terminal. good luck.

You have a power drain ...and it sounds like a big one. Basically there will be a short somewhere in your cars wiring causing the power to drain from your battery, I would also check your car stereo wiring as sometimes they are the fault

Make sure that there are no lights or components running in your vehicle when it is shut off. If your battery is loosing power when it is off then it is a shot battery and you need a new one. if the battery is going dead when you drive then you have a bad alternator. good luck

make sure your ignition switch is really shutting off and not staying on even though it looks off

As the car re-started, the battery is not flat.
The voltages measured indicate a problem with either the power or ground connection in the circuit between the alternator and the battery.

You likely have a intermittent / poor ground connection somewhere in the power system.
Check battery terminals are clean and firmly attached.
Check battery cable and alternator ground connections are intact and in good order.

sounds like you have a shorted wire somewhere.