1993 Lexus Dashboard lighting

Electrical problem
1993 Lexus V6 Two Wheel Drive Automatic 138000 miles

Model LS400 - Dasboard lighting goes off after I start up in the morning. It remains off for about 1hr then flickers on. It is getting progressively worst. Generally, the colder it is outside the longer it stays off. Also, gas gauge doesnt' work but low level waring light does. What should I have repaired or replaced?