Good Morning,

I am having problems with my vents. When i have the setting on front defrost only (ac light off) air blows through the two front dash vents. If i switch it to front defrost and feet, the AC light automatically comes on. Also, the back defrost does not work. Is air suppose to blow back there or is it through the lines that are in the back window?

 

Do you have manual or auto HVAC?

Have you tested the mode control motor to be sure it is working and the linkage is not in a bind.

The rear is electrical, again several tests need to be done to find out what is going on.