1990 Cherokee interior and dash lights not working

I had the exact same issue as well, I had to take out the whole dash and go threw the whole wire harness from the fuse box throughout the whole dash and also threw the fire wall. I checked the fuses first and of course they were blown, then they still didn't work, when I was in the wiring harness I found 7 wires melted together and had to replace them all. After I did that they seemed to work just fine. I do still have one issue and that's that when you turn on the headlights the interior lights shut off regardless of the door being open. I still have not figured this one out yet. All wires are fine and fuses, I don't know what else to check. Hope I helped a little.