Quote:
Originally Posted by Brian Carlton
I never measured it, but AFAIK, the monovalve always gets a 12V supply and the CCU switches the ground on and off to maintain cabin temperature.
I'm not sure of the frequency and the results that Kerry observed might be the normal switching of the valve. I have a suspicion that it does quite a bit of shuttling back and forth.
When the pump was marginal, you could hear the monovalve cycle inside the cabin. That prompted me to immediately disconnect the pump and the monovalve then became quiet again. |
That, more or less, agrees with my understanding of the monovalve design (but I didn't know the switching was on the ground side).
I don't have a clue how/why the pump and the monovalve interact through the CCU, I still think it's magic.
