Gaauges not working

I don't have wiring info on your model year. The sending units for temp and fuel should control resistance to ground. The temp gage on the engine block, the fuel sending unit should be in the gas tank. An example, if you take temp sending unit, electrical, connector loose, key on, touch engine ground, the gage needle should move, then you suspect the sending unit. With electrical sending units, could be problem with wiring circuit--sending unit-- no voltage-- faulty gage?

As far as too much battery drain. You can take a battery cable loose, use testlite between cable end and battery post. If the lite comes on, pull and replace fuses one at a time, when you pull the fuse on the problem circuit, the lite goes out. Make sure all interior lites are off.