ATC Window Blank

[scnrfrq1]

When flying the Arrow, the ATC window is blank except for the freqs at the top. I get a quick message about the electrical system in the window. How do I get ATC to work?

[Sender46]

@scnrfrq1 You need to turn on the NAV radios first in order to be able to turn on the COM radios.

I think they should be able to be turned on independently but I think I recall JF saying that's a limitation of MSFS.
https://community.justflight.com/topic/2972/com-nav-issues/11