1998 GMC Envoy Owner's Manual - Page 101

You can use the DOME OVERRIDE button, located below the parking/headlamp knob, to set the dome lamps to come on automatically when the doors are opened, or to remain off. To turn the lamps off, press the button once into the "in" position. With the button in this position, the dome lamps will remain off when the doors are open. To return the lamps to automatic operation, press the button again and return it to the "out" position. With the button in this position, the dome lamps will come on when you open the door. This will not override the illuminated entry feature. Mirrors Electrochromic Daymight Inside Rearview Mirror Battery Run-Down Protection This feature shuts off the dome, courtesy, vanity, reading, glove box and underhood lamps if they are left on for more than 20 minutes when the ignition is off. This will keep your battery from running down. If the battery run-down protection shuts off the interior lamps, it may be necessary to do one of the following to return to normal operation: 0 This mirror automatically changes to reduce glare from headlamps behind you. A photocell on the back of the mirror senses when it is becoming dark outside. Another photocell built into the mirror surface senses when headlamps are behind you. At night, when the glare is too high, the mirror will gradually darken to reduce glare (this change may take a few seconds). Themirror will return to its clear daytime state when the glare is reduced. The vehicle will also return to its clear daytime state when the vehicle is put into REVERSE (R). Shut off all lamps and close all doors, or Turn the ignition key to RUN. 2-40