There are all kinds of wiring diagrams on the internet, and most of them make no sense at all. Just use some logic. Start at the end (The switch) with a multi-meter and check to see you are getting right at 12 volts there. If you are, then the switch is bad. If not, then go down river and find where there may be a bad connection. Just keep going all the way back to the fuse box. You will find it. It just takes a lot of sweat in this heat to stay under that dash on your back. I know, I know....it is painful...especially at my age.