Okay, checked the bulbs, the door ajar whine works when I open the door, so the door sensor is okay, played with the dome light override button, and can hear a relay clicking on the other side of the van, tried the little dial next to the dash lights. I dont have DRL even though the DRL dash light is on (related? I dont know, dont care if the DRL gets fixed but thought id just include it). Checked every fuse, all okay, no open spots in the fuse block (but the fuse door is missing, so I really dont know what fuse would control the interior). The only thing I can think of is that the harness is unplugged, but figured Id ask before tearing the interior apart. Oh, it is a 99
I had a Chevy Express 2000 van for awhile and one day all of a sudden the interior lights would not come on. After a lot of investigation, we took it to a Chevy dealer and they found a short in the lighted vanity mirror in the driver's side visor. Once they fixed that there was no more problem. I hope this helps.