Found this little gem while trying to fix the same third row seat blower issue above.

MC-10147261-9999.pdf

Yes it's for an F15 but the system is essentially the same,.

Reading between the lines... slightly fold the right hand third seat forward to expose the control unit, carefully unplug the two plugs from the back of the unit. cycle the ignition, plug the unit back in. If you have an ODB II, reset the associated 9C56 code and restore power to the HVAC climate control.

Press the button and hey presto.

If fault persists, you've likely got a wiring or liquid ingression issue.

All the best.