lights out

Most trunk lights have a mercury switch in the socket or a button somewhere near the latch that is a switch to turn the trunk light on and off. I have seen a few cars where the trunk light circut is only active when the cars headlights and/or parking lights are turned on.

Try the light with the headlight switch on and see what happens. Otherwise the socket or the switch may be out of adjustment or defective. Make sure the bulb is good by testing it as well. Sometimes new bulbs out of the package don't work.