Re: Finally...

[Wallace White <wallace@remdesign.com>]

Marty -

I would just add one thing to Aleksander's response: the "heater
programmer motor" (that's the right name, in fact) is an electric motor
that controls the position of the temperature flaps. Basically it does
the job of the slider in most cars that goes from cold to hot. It's not
uncommon for them to strip a gear or break in some other fashion. 
Usually, if there's a problem with this motor, you get an error on the
climate control head. It flashes the Outside Temp light to let you know
of the error. If you're not getting a flashing light, and you are
getting the temp. of air that you asked for, your motor doesn't need
replacing.

But, the programmer motor doesn't control the air distribution flaps,
which are responsible for all your air coming out at the defrost vents.
Defrost vents are the default position of the flap system; if the flaps
won't move to any other positions, then there's something wrong with the
solenoid valves or the vacuum system of the flaps. (Vacuum is connected
to four solenoid valves on the A/C programmer board; each of those
valves is connected to one or two "vacuum motors," which are just
pistons.) 

First thing to check is that all the hoses are connected and not
leaking. The vacuum piston for the recirc flap often comes disconnected
from its hose, meaning that you get a vacuum leak anytime its solenoid
valve is opened. One leak and the hole system loses vacuum, bringing you
into the default mode (defrost only).

And about the owner's manual: the more important manual to have, if you
plan to work on the car yourself, is the Bentley factory service manual
(about $100). You can get it and most of your parts from good parts
stores like The Parts Connection (on the vendors page Aleksander
mentioned.) Good luck!

- Wallace
  '87 5kcstq 153k