I had a hard time just figuring out how to use it for the first while. Not to insult; you can ignore the following if you know:
With the dasboard rear fan controller on "RR" the roof fan controller is enabled. It has 3 speeds.
There are only 2 speeds on the dashboard rear fan controller. LOW is the click above "RR" and HIGH is the click above LOW that. Using either of the 2 speeds on the dashboard rear fan controller disables and overrides the roof rear fan controller. Hot comes from the vent near the 3rd row right passenger's ankle. Cold comes out of the roof vents. The temp is set by the driver's temp slider. Only full hot or full cold are available, nothing in between. Once the rear temp is set, then the fan turned on, the front temp(s) can be adjusted.
On RR do you lose speeds 1 AND 2?