**is there a fuse or something that would trigger this light to turn off?

 

Meaning the defrost window and the rear window buttons are not lit.

 

there are tiny "rice lights" in for the buttons that 99% likely have burnt out. If I remember correctly sometimes one bulb will light up a few of those buttons. The service manual describes how to replace them... its quite involved - you have to pull a lot of trim and parts to do it