Rear climate switches to feet on its own

[teg916]

I have a 2017 Dodge Journey, only 24K miles on it.  The rear climate control acts up and will not stay in the position where it blows air from the overhead.  It keeps switching back to blowing on your feet on its own.  At first I thought it was the rear controls.  I popped them off of the ceiling, and cleaned the wipers, but it still does it.  When I select air to blow from the overhead, it does switch to the overhead vents.  Then it switches back to the foot vents on its own.  Sometimes it switches back after 3 seconds.  Sometimes it is after a few minutes.  Not sure why.

 

I was going to replace the rear controller, but then I noticed that even if I lock out the rear controls, it still does it.  When I push the lock button, nothing I do on the rear controller should have an effect on the system right?  I can't change the fan speed from the rear controller, or the temperature.  But which vents still switch to feet.  This makes me believe something else is the cause.  Any tips on figuring out what is the cause?  Does anyone have a link to a good description of how the system works, or a wiring diagram for it?

 

Thanks.