Temp gauge is probably a bad sending unit on the top of the intake manifold (close to where the upper radiator goes or mounted straight out the front above the water pump depending on which engine you have). Should be a single wire connector that just pushes on. Ground the wire and the gauge should peg. If it doesn't, the wire has an open or the gauge is bad. The fuel gauge is also probably its sending unit in the tank depending on how it goes bad. Car is old enough though that the connector and ground wire at the tank need to be checked for corrosion.
