A/C not working correctly
 

Hi everyone,
​​​​​​I realised that my AC works on the "upper body and feet" mode but doesn't works on the "feet only" or "upper body only" mode. Also, my AC works on his normal mode: "AC" and "Max AC".
My question is why does it works on the "upper body and feet" mode?? It should not work normally...
​​​​​Did someone knows how to fix that?
Thanks a lot guys!

[Truck's specs:
2006 Ford Ranger FX4
4x4 - Auto - 4.10]

OliverFord