Hi all could anyone tell me if they no what is wrong with my heater when switched to either number 1 or 2 it dont work but when switched up to 3 or 4 it does work. It was working fine before for the past 3 weeks i have had the car. I done some hoovering in the footwells today and it was after that i noticed the issue. I read somewhere on here about checking the connectors in the passenger footwell and i have done this but still not working so if anyone has any ideas on how to fix this i would be greatful for the help