87 Aires map light.

Hello, all. I've just acquired a 1987 Dodge Aires LE and am trying to restore it. It's been taken care of so-so in the past and is in great condition, with the exception of a few minor things. The one that's confusing me the most now is a nonfunctioning map light. It's the one that's in the passenger side sun visor by the mirror. I've taken it apart and replaced the bulb with a known good bulb and it still fails to light up. What controls the map light? I've tried using the dome light switch in the main lighting switch (Turned completely counter clockwise) and the dome light comes on but not the map light. All door switches seem fine. I've checked all of the fuses and they're all good. I can't find any other switch that controls the map light. I can't figure out what causes it to light. I've tried pulling it out, aiming it right, left, up, down, etc. and no go. I don't have a factory manual and numerous web searches turn up nada, 0, zilch. Anyone know how to get this to work? TIA.