True to form, my BIMMER has HVAC problems... Have traced a vacuum leak to a blue vacuum hose attached to a relay not related to the set of 5 or 6 in the center of the dash, located close to the fire wall and to the left of the glove compartment. Can't tell where the hose goes as it disappears up into the dash. I assume that the HVAC vacuum hoses are color coded for function since none of them in a common area are the same color. Would like to have a diagram with color codes so I can determine which vacuum motor needs replacing and if it is worth all the trouble to fix. I have clamped the hose off stopping the leak and the system works normally, as far as I can tell. Anyone have that kind of info available?? Thanks in advance