First so we are speaking the same lingo, the button you are referring to is Recirculation/Fresh Air button or RECIRC for short. I would also like to see this from the OEM panel as we checked our code and we only send the HVAC the single bit to reflect that the RECIRC button has been pressed. The OEM climate control then responds back with a status message and we update the icons based on that. We do not have any logic to turn anything on or off with the RECIRC button.
Please tell me what happens when you press the POWER button (top center button). We believe this will turn off the HVAC system and close vents as you want. If so, nothing to do here.
If not, please shoot a video and then PM me and I will provide a place to upload it.
Maybe someone here could verify how it works with the OEM panel or you could pop your stock stuff back in and see.
We have access to a Mustang but our contact is on an extended vacation at the moment.
LOL...I should have stated but the picture I used as the Kenwood reference was something I found on the internet. Just to show you the button configures. Not my actual screen. I guess the only thing I can do is to record it. I will record it and post it up later tonight as I have to get to work soon.
I can tell you right now how the OEM works. AS how it would work in every other car as well. It is not just the Mustang, every car has this button and it works independent regardless if the HVAC was on or off. Go out to your car and test it... You can reference the picture I posted. You can toggle it open and close from the push of that button you see on the OEM panel. (Picture Attached from previous post).
Like I said...DEFAULT the MAESTRO has the vents OPEN with HVAC system turned off, when I go to CLOSE the vents the MAESTRO turns on the AC and CLOSES the vents. When I push the POWER button to turn the AC OFF, it turns the AC OFF and REOPENS the vents. MAESTRO will not allow you to close the vents without having the AC turn on. Video later when I get home from work if you still do not understand what I am saying...