when my 02 impreza hvac selector is on floor only hot air comes out through the floor and defrost vents, all other selections work as they should, i looked at the hvac cable ,actuator and doors and they seem to be working properly besides not shutting off the defrost when the floor only is on. is this normal for a 02 ? my 93 did not do this.

My '93 did this after I put the dash back together from a heater core install. I think it's just a matter of the adjuster knob moving slightly too far and starting to engage the heat/defrost selection.

 

I just consider it a convenient "extra" option.