Ok let me try to explain this. My blower works fine on all 4 speeds. But I have to move my heat switch back and forth to make it come on. And defrost never really comes on. The a/c also does not come on. I can hear the compresser kick on. Just trying to figure out how to make the heat work without having to jiggle the switch and how to get some defrost. When the heat comes on it blows nice and hot.

 

I think your switch is bad. That's what mine did. And then it hit the pooper now I only have low...

 

mine acts kinda like that too, i have to put it on "vent" for the heat to come out