Blend motor is the most likely. I never run it on Auto as it uses the blend motors more. Only way to be sure is diagnostics. No urgency if the cabin temperature and distribution is OK.
press all the buttons until it goes away - same theory on a B737!
deffo not going in a plane with you!
Shame a p38 doesn't have circuit breakers you can just pull to make annoying things go away.
its ok - its all legal to do that sort of thing if you're flying there
:d:d:d:dbolliocks! :d:d:d:d:d:d