Pulling the UPPER hose off the AAR should have no effect at any temp; if
it does, then the hose is plugged. Pulling the lower hose off the AAR
should make the engine race at any temp.
I took Dave's advice and submerged it in hot water and it does in fact
tighten down when hot and close off air flow. What I'm still stumped on
is the fact that the aux air reg seems fairly closed even when at room
temp - which is when it should be more open. Have not found any
documentation on what the little + and - signs mean on the little
spring.
It is normal for it to be mostly closed at room temp. It will be mostly
open when it gets well below freezing. Unlike the engine cooling
thermostat, the AAR does not open/close all at one temp; it closes
slowly over a rather wide temp range as the engine warms up. The +/-
indicates which direction you should shift it to adjust exactly where
that range falls.