Bora Rear Heated Screen Not Working

[Wisey]

Have had my bora for a few months now and the rear screen has never worked, and thought I better get it working before winter 
 
When you push the button it doesn't light up and the screen doesn't heat up... Is it a problem with the switch or is it a problem with the heated element on the glass? I have had a look at the element and there is no breaks I can see in it. Have also had a look at the fuses at the drive's side of the dash and can't see any blown ones 

Does anyone know where the earth is for the rear screen and where the power connects to the element before I go stripping everything out 

[mcgee9t2]

power isnt getting to the switch otherwise it would light up.

id replace the fuse just to be on the safe side. id also take the dash vent out and make sure the switch is plugged in. if you still arent getting power to it trace the wire for any splits or snaps, and if possible use a multimeter.

once you have got button to light up test it out, if the heating element still isnt working have a look at the wires in the rubber chanel going from your boot to roof (can be seen when opening boot) the cables oftern snap in there...

however, if power is getting to the switch it should light up...