Manual climate control 2013 R57. Press the AC button and the light doesn't come on. Press the rear defrost button and the light doesn't come on. Recirc button works as expected, fan control and diverter seem to work as expected. Re-seated all the connectors on the back of the control panel - AC was working before I installed a new stereo - no change, could be coincidence?

Any ideas on what I should check? If it was the front defogger, I would just start going after AC "things" but I am thrown off by the rear defrost not working.

 

The AC and rear defroster (among other things) are controlled by the JBE module (built into the fuse panel). It receives signals from various other control modules such as the climate control module via the CAN network to determine what things to switch on/off. Even though you have manual climate, there's still electronics in there connected to the CAN. If there's a disruption on any CAN signal, things go haywire.
If you have a Mini specific scan tool you can do a whole vehicle scan and determine if there's any signal faults. It's entirely plausible the new radio is causing this. In fact, I've seen it firsthand in the past.
If you don't have a proper scan tool you can try unplugging the harness from the back of the radio to see if it corrects it.

 

I got a decent code reader.

4 IHKA faults all related to flapper motors. Code reader tells me A/C control button is operable, the fan diverter **** is operable, the temperature set point is operable, but the fan speed reads as pegged at 100% even though I can turn the **** and the fan adjusts accordingly.

What do I look at next?

 

What are the faults codes?
Are there fault codes in any other modules?