My dash lights turn on for maybe five seconds, it makes thing clicking noise where the switch is and then goes out. Also when it goes out my horn doesn't work. But my horn does work when light switch isn't on. Interior light and outside lights work but flicker. It's a 1980 Ford f150

 

The solution may be as simple as a new battery, also check all of your fuses and make sure that the wires are all done up correctly with no loose contacts. I would suggest pulling your fuses and using a volt meter to test continuity first, if they're all good then move on. I know my 1980 f150 351 w had a flickering problem in the winter with the headlights and dash lights until I replaced the battery.