I do have the red switch, but does around 250 still seem high for the fans to come on? Also the temp wheel has to be on "MIN" before they come on. Could my switch be malfunctioning?

Does the multi outlet valve have all the vacuum lines plugged into it? If it does, I've seen that behind the glove box.

Off and On I do get a loud clunck from the center of the dash. Could this be the vent flaps stuck?