Since tidy ing the wiring behind my dash the main beam switch doesn't work
I have 12v at my dip switch but not 12v at my main beam switch
What I can't get me head round it has 12v at the terminal and zero at the other but when switched it has no output at ant terminal
On my main beam I have no power at all
I don't understand how earth switching works
Any one explain in idiots terms how it works

What switch??

Toggle switches simple on off ones