Illuminated window switch working but not illuminating

[ThomasBellamy]

What could cause this?

The switch in there at the moment currently has blown bulbs, however when I switch with a working switch that doesn't light up either.

I have a new working switch to replaced the old one tonight, however it won't light up. The switch and the windows work perfect it just doesn't light up.

How I fix?

[Brianmoooore]

Should be impossible! The wires to the switch that illuminate the bulb (green/grey and brown) are also used to work the windows. If the windows work, the bulb should be lit, unless it's blown, of course.
The bulb is easy enough to change, using suitable replacements from the likes of CPC-Farnell.

[ThomasBellamy]

It works now, I don't know what I was thinking

[Brianmoooore]

Only lights up when the window circuit is live. Nothing to do with the rest of the panel/instrument lights.

[ThomasBellamy]

Only lights up when the window circuit is live. Nothing to do with the rest of the panel/instrument lights.

I know now, when I checked it a few weeks ago I probably didn't plug it in properly or something.