I am having3 problems with my 99' Cadillac Deville Concours

First, the interior lighting is not working. The dashboard, radio, and door lights seem to be working fine, but allthe overhead mirrors, reading lights, cigarrette lightersand dome lights do not work. I changed the fuse already for INT LIGHTs but it did nothing. Someone told me there is another fuse box inside the car but I can't seem to find one.

The next problem I am having is the fuel gauge. The needle in the gauge fluctuates everytime I start the car and sometimes while driving. It seems to mostly read a full tank. It always looks like a full tank until right before I'm about to run out of gas and then the needle will shoot down to E. I'm thinking ,maybe sensor, fuel tank, or the sending unit?

Lastly would be that the mesage display keeps flashing LOW REFRIDGERANT- A/C OFF. I think it just needs a charge. I'm wondering if it could need a new condensor?

PLEASE HELP ASAP!!!!

 

Cigar lighters - Check fuse in underhood fuse block.

Fuel gauge - Could be sensor / sender assembly. Check for codes

Interior lights - rear fuse block is in trunk. Check for codes.