Here in the US, the button on the right is usually for the same thing - the AC. But, I don't have A/C.

I was just trying to clean up the dash area some.... I just had a switch blank where the AC button should be in my climate control panel... so I got an AC switch, and modified it a little so that it could replace the rear defroster switch in the dash. The switch in the lower instrument hood on the '91 (maybe other years too) is combined with the dash brightness controller. I didn't really need that either (Indiglo gauges, etc), so I removed the switch assembly and made a new insert that has only the Indiglo gauge controller.