Problem with heater fan direction ?

All the blower does is send airflow into the system.When you move the lever or push the buttons to switch from defrost,vent,floor,etc doors located inside of the housing under dash open and close in order to change what vents the heat/ac is gonna come from.Fan has nothing to do with where the air comesout. Doors are controlled by actuators and/or vacuum motors located in that housing.You can also find the vacuum motors sometimes by lowering the glovebox,the heat/air control panel,or by looking under the dash.Check the vacuum lines connected to vacuum motors for cracks,splits,leaks,or bad connections.Make sure the motors getting proper vacuum.Check the actuator doors for proper operation.There are also fuses or relays that control the door actuators and control panel,so make sure none are blown.Check wiring to components too.Its usually a fuse,loose connection,bad actuator,vacuum motor,or damaged vacuum line that causes your problem

Maybe something fell into the windshield vents and holding it open, or I don,t know if you have vacuum control to vent controls maybe a vacuum line is lose behind the switch.

check to see if you accidentally reversed the wires....the electricity would flow BACKWARDS through the motor windings and cause it to run backwards...and maybe cause damage to the motor