Farmlifer,
A general rule to keep in mind when working on any aspect of an automobile.
Simplest things first. then work step by step up the system from simplest to most complex.
So for example as in your issues:
fuses
bulbs
wiring
connections, at the bulb, wiring harness, at the switch, etc, etc,
switches
What this does is helps prevent spending money and replacing parts needlessly when perhaps the problem was something very simple and basic.
I have seen people replace starters just to find out that they had a bad connection at the battery
Hope this helps.