Get a 12v bulb tester and test both wires ontop of the switch one will have a live to it. If none are live suspect a fuse blown. Other than that broken wire which i doubt but it happens!
If you have replaced the switch then obviously it is not the switch that is at fault best way to find this out is find the live and connect it to one side of the switch connect your 12v tester to the other side of the switch i mean the terminal. Make sure your 12v tester is hooked up to a good earth otherwise the bulb wont work. Press the switch and see if the light goes on or if the light is on if it will go off.
The switch itself the button at the bottom should pop out as it is on a spring make sure that this button is moving it must not be seized or loose in other words it should push back out once you let it go.
Carlito Corway
January 2008