i have an FX4 xcab with tow package and mirror package (rearview mirror sensor and signal lights on sidemirrors), i thought that i had heated mirrors, but i see no button to turn them on, nor when i drive, do the ice and snow automatically melt off. anybody know?

 

If you have the rear defroster, it is the same button. if not, it is a button undereath the vent selection control.

-ii

 

I have a 4x4 Scab Lariat and it is the button right below the front windshield defrost button. They look almost identical.