1998 Chevrolet Astro Owner's Manual - Page 123
1998 Chevrolet Astro Manual
Page 123 highlights
The dome lamps will come on when you open any of the doors. They will remain on for 20 seconds after the last door closes. When the ignition switch is turned on, the dome lamps will go off. You can also turn on the dome lamps by turning the dimmer dial up to the second click. If the DOME OVERRIDE button is pushed in, the dome lamps will not come on. If the DOME OVERRIDE button is out, your interior lamps will work asusual. If the button 1s pressed in, the interior lamps will not come on when any of the vehicle'sdoors are open. The button is located next to the lamp switch. If you have the optional reading lamps, they will still operate if the button is pressed in. Dome Override Button Reading Lamps (Option) You may have the optional reading lamps next to the dome lamps. Turn the lamps on and off by pressing the switch next to the lamp. You can adjust the lamps to any desired position by rotating the lamp and they will work when the ignition is on or off. Be sure to turn the lamps off before you leave the vehicle.