Try this link.
http://drivers.lexus...pdf/6-4_216.pdf
That's the relevant owner's manual section for your LS400
It seems fuse 4, 5 which are the radio and cig maybe out. Also number 20 which is your dome fuse may be a possibility too. You should really check out the link and see for yourself.
The fuses are located in the driver's side kick panel which (correct me if I'm wrong) would be our passenger side.
The relevant information are all on the first 5 pages.