Heating can no longer help !!!!!!!!!

Hello dear people hope you can help me further and hopefully quickly have looked at the sufu and entered everything possible but found nothing!!!!! so it’s about the car of my mother is a Ford escort capriole where flashers and headlights are separated. She drove with the car quite normal and turned on the heating and suddenly she went out and no longer on. I’ve been at the scrap site and have asked for a switch also got one and built in and it still didn’t work that way have taken the switch away again and that the already inside was made back in like that. then I had on the scrap space a new heating engine with resuscitation brought out old motor out new motor in with resuscitation tried still not is slow to despair wants to go to the scrap site again tomorrow and let me give the switch again to see if both has broken but can’t imagine that because both or three at once ??hmm….and I’ve also looked after everyone in the green.so now my question what can that be cable also seem all okay. hope to answer quickly