5000CSTQ Heater Controls

[nicosisj@ldcl1.dnet.dupont.com]

The electronic controls for the heater/ac system in my car have a problem.
With the controls set at 72 the passenger compartment warms up in a normal
manner.  As the the temperature reaches the set point(72) the fan speed slows
down as it should but the air temperature continues to go up.  There appears to
be no control on the air temperature.  I read some of the archives and recall
something about a bowden cable and electric motor that control a mixing flap.
Can anyone give me more specific info on these and can this be the problem with 
my system?  

Any help will be appreciated...

Sal Nicosia
'87 5000CSTQ
'91 MB300E