Re[2]: Heat/AC/Fresh Air Flap

[J_T_Douglas%mwcorp1@MWMGATE1.mitre.org]

    I'm beginning to suspect that my A/C suffers from a combination
    of problems.  It seems to operate in three distinct modes:

    1. More or less OK: Compressor kicks in, temperature control has
    the expected effect on blower fan speed/air temperature.  Air never
    quite gets as cold as, say, on my '92 Accord which leads me to
    suspect that hot air is getting mixed in somewhere.  If the car's
    been sitting out in the sun all day, this is the mode I get -- so
    I rarely have a problem driving home.

This could be a number of things (of course - mechanical problems can always be 
a "number of things!"), but the most likely one is that your system is a little 
low on freon.

    2. Foot-roaster: The climate control is off, but there's a hot
    air draft in the driver-side footwell: in half-an-hour or so, the
    driver's feet (usually mine!) are uncomfortably hot.  This usually
    happens while driving long distances on cool nights.  A/C works if
    turned on.

Is it only on the driver's side?  Very strange, if that is the case. :-)
Seriously, definitely sounds like its the same problem as number 3.

    3. Gasoline-fired oven: Compressor will not turn on, all modes
    (including ECON) blow hot air through all vents.  Turning it off
    helps only slightly: there's still enough of a hot air draft to
    make things really uncomfortable.  Usually seems to happen on cooler
    days, and seems to fix itself after a couple of hours.

Just a guess, as I've never had to really tackle the beastie, but it does sound 
as if one of the flaps in the mixing box is not moving.  Another thing you 
might want to look at is the vacuum operated valve on the coolant line that 
runs to the heater core.  Does it move properly when the temperature controls 
are adjusted?

Unless someone here knows the answer off the top of their heads, it sounds like 
you definitely need Bentley.  Did you say your car has the newer controls?  How 
lucky, because Bentley tells you how to get tons of data (e.g., sensor 
readings, actuator positions, etc.).

Jason