Driving my cls220d last night and noticed rear Demister Switch was dim. When I pressed it to turn it off the whole climate control started going haywire randomly blowing hot, cold, max power fan to low, lights on climate panel flashing and also bottom of main screen information flashing. Only thing that stopped it was turning car off. When turned back on rear Demister button dimly lit and everything else seems OK unless I press the Demister button then it goes haywire again.
Any ideas with what might be wrong?
Any ideas with what might be wrong?