83 a/c - evaporator/heater housing assy

[DavisADM@xxxxxxx]

I have to remove the evaporator/heater housing assy to replace a leaking 
evaporator core, and as I'm sure you know this is an involved task.  I would 
like to make sure everything else is working before I put everything back 
together.  I have had problems with the S.A.T.C. (semi-automatic temperature 
control) not working properly at times.  It would blow warm air when the temp 
lever is set to minimum.  Then the next time I drive it, it blows cool.  Upon 
start up, I can hear the electronic servo motor turning.  I don't know if 
there is an accumulation of dirt or debris that is preventing the blend door 
from closing, or if something else is wrong.  What should I look for when I 
have the assy out of the car?

Thanks,
Davis