Some years used a courtesy lighting lamp delay module (Theatre lighting) to delay the interior lamps. I had a '97 which had such a module. When the module failed, the lamps would remain on constantly. If that is the case, you can simply unplug the module and the interior lamps will operate directly from the door/gate switches with no delay.
The module would be located above the lower edge of the instrument panel, near the left kick panel. I'm not certain if a 2000 MY used that device, however.