Dash and Climate Control Units on 87 Eldorado Biarritz

Both the dash and CCU went dark no light. All the buttons works, blower work, AC works, Turn signal and lights inside and outsides works. But can't see anythings are the dash and CCU is dead. What can cause that and how to fix them. Checked fuses looks OK. Don't where to go from where. Trying to save $$ as do not have lot in the first place. All help is deeply appreciated. Thanks.

MK