AC changes 0n '90 200

[cobram at juno.com]

Does the air go to the defroster?  If so one of the solenoid actuated
vacuum valves in the programmer is most likely at fault.  

About 2 years ago I have a similar problem manifest itself in my 1990
200TQA under acceleration (everything works perfect, but once I
accelerate the car, what you described  happens with NO air coming out
anywhere, including the defroster.)  My solution...turn the control unit
up from "low" (no temp in display) up a notch till it reads the lowest
temp, I think 64 degrees.  Once it has a numeric value in the control
head,  everything works just fine, turn the temp all the way down and the
problem starts again.  I changed the programmer with a known good one and
it didn't fix the problem.  Since the hack is working fine I haven't gone
the next step to change CC head unit.

BCNU,
http://www.geocities.com/cobramsri/
We come into the world naked, screaming and covered in blood. Why should
the fun end there?
 
"nick at beol.net" <nick at beol.net> writes:
> Vehicle is '90 200 tqa.   Often, in hot weather when the AC is on 
> auto and  
> cold air is blowing out of the dash vents, something changes. The 
> fan  
> still is blowing, the ac clutch is still clutching, but the air no 
> longer  
> comes out the dash vents.  Very likely a door is changing positions. 
>  Can  
> happen at idle or at speed. To get the air back out of the center 
> vents  
> turn off the ignition and back on.  Turning off/on the climate 
> control  
> won't bring it back.
> Has anybody seen this and figured out what to fix?
> Any suspect that the servos simply leak off?
> 
> TIA
> Nick