1994 GMC Safari Owner's Manual - Page 105

Interior Lights Override Switch . '. , . position, your interior lights will work as usual. , ' If the switch is OFF, the interior lights willnot come on when anyof the vehicle doors are open. It is on the instrument panel above the radio. If you have the optional reading lamps, they will stilloperate if the switch is in the OFF position. Mirrors Inside Mirror 2-45