I think I got it. I had to turn off engine air. Once I got the thing to turn on, a little trial and error (and some virtual carnage, lol) and I think I have it now. Pretty neat.
This panel is really amazing. I am flying the HJG Murchison model 146-300 and the -300QT. I've been fascinated with the 146 ever since I saw one in real life at EGPF. I've flown on the Aer Lingus 146-300 in 2003 from Dublin to Glasgow and back, and it was really interesting to learn a bit about flying it in MSFS.
Thanks again for all the time you put into this panel and supporting it.