If you don't already have one, a good manual is valuable and they have a full circuit diagram to help trace problems.
Without knowing any specifics on the problem (or model), electrical faults with lights/switches are often loose connections, or damaged cables, assuming the bulb/switch/fuses etc are OK.
Engine electricals are a whole different ball game!
If your mechanically minded and follow it through they are not that hard to fix, so good luck!
Oh,
Welcome to the forum!
So are you really Lucylawless? 馃榾
Richard
Andy 路