2002 1500HD Dome & Map Light dont come on
 

I have a 2002 1500HD that has recently devoloped a problem. The overhead Map lights and dome lights do not come on any longer when unlocking the truck with the FOB or when opening ANY door. All four interior door lights and the lights that are under the dash (the lights that shine on the floor boards by your feet) come on when I do either (unlock with FOB/open ANY door). Now, before you say "check the override button", I've done this and it is in the correct position because in one of the positions (I believe the "in" position) the door & floor lights do not come on when opening the doors. Also, I can turn both the map and the dome lights on with their manual switches. I can not however force them to come on with the "dimmer switch" in the full up "clicked" position. When I do this, again, only the door & floor lights come on. I've checked the CTSY fuse under the hood and a couple of fuses in the drivers side fuse box. When I pulled these fuses out...the door & floor lights go out..so I believe they are good. Any advise?