on a 96' impala, the door pin is just an input to an electronic module. computer then decides, based on pin switches & various other paramaters whether to engage the relay which turns on interior domelights.
if you get desperate, could pull all the domelight bulbs out of their sockets and carry a flashlight in the car.
or there's always http://www.alldatadiy.com
is not cheap and the $25 fee only allows you to access one car. and after a year, you need to pay another $25 for another years access. gm shop manual is much better investment if you plan on keeping car for a while.