Speaker and heated screen

The day i got my Disco i pressed the heated rear window button and it worked...Not for long!
It's completely stopped working, The light on the button doesn't illuminate and the window does not clear.
Also the speakers in the back door do not work.
Are these related, as i presume the wires run side by side to the boot door.
Ta,

For the speaker have you unbolted it and checked its connected as i throught mine had broke so when i took it off it was simply not plugged in.as for both connected check fuses in handbook. I doubt they are related but still check fuses for heated rear window also could be faulty switch