Are the posts if the switch labeled? You might have the ground on the wrong side. The switch itself may not be grounded correctly. Do you have a test light? I would pull the switch and test it's operation with some jumper wires using the car's battery or another 12v DC source. I have a Power Probe, kind of a pro's tool and little expensive, but once you own one, you'll never want to be without it.So I found this diagram as well and it resembles how I am wired up, but it’s different from the diagram above but the same switch.