A couple of people had said their clock doesn't work, door opening shuts off clock or interior lights don't work. I had the same problem and when I looked at everything, it was fine.
Checked the fuses though and turns out the 7.5 AMP was toast. Replaced it and volla! Everything works fine!
Just to let others know if they have that problem a solution that I found.

 

ok.... thats a rather vaugue representation of a fix because i have replaced all my fuses when i bought my 86 GXL nearly 4 months ago.... my clock randomly works(the idiot cluster itself) and my interior lights wont come on cause the door sensor doesnt make good contact(needs a jiggle every now and again)

if a fuse fixes it.... be weary... the same symptoms can show again and the problem wont be a bad fuse.... it could either be a bad relay, switch, or the wiring/solder joints are corroded/dirty

 

I kind of blame myself, I was working on the dome light part cause it was loose, made a couple of sparks and thus, everything went hay-wire.

Sorry if it doesn't fix your problem but it helped me out.