I have a '93 F150 4x4 Supercab Full Box
My fan works fine on high, but on the first (1,2,3) settings nothing happens. I checked the fuse and it appears to be good. any help would be welcomed as winter is coming.

 

Give this a read:
https://www.f150forum.com/f10/c-heater-control-issues-10983/

 

thanks for the reply I'll will check it out this weekend.