Courtesy Lamp: Description and Operation

Battery voltage is applied at all times through the CB-5 DOME LIGHT fuse to the dome, map, courtesy, and luggage room lights.

Courtesy Lights (Amigo w/Preferred Equipment and Rodeo LS and LSE Models)
With a door open, a ground path is provided by the alarm and relay control unit through the left front door switch, or any of the other door switches, and the door courtesy lights go on.