Would have thought the power supply to heated screen would be via "run" position on ignition switch. If so there is something more sinister at play, maybe the BCU.
On my Roadster the BCU controls the power to the screen heater and the switch is just a trigger for this. A further push of the switch cycles it off or it simply times out. The switch has its own illumination, dim or bright depending whether screen heat is on or not. Does yours function in similar manner when working correctly?
Last edited by Richard Wood; 28/05/20 01:44 PM. Reason: Removed reference to earlier switch type
