There could be a number of things that is causing your problems. The first thing to check is the fuse box and the different fuses that power up the different systems that are out. The second thing to check, if the fuses where good and the different fuses had power going to them when you turned on the ignition switch and light switch, would be to check your different connections for the instrument panel. Make sure that you have a good ground connection to the instrument panel printed circuit board. That is the main connection that will tie all of the items that you are having problems with together. You are working with D.C. current, which has only two connections that will make an electrical system work and that is a positive and a negative connection that has to make continuity through whatever you are working with, be it a light bulb or gas gauge.