hvac issue with blend door

[chris_19]

i have a 96 olds supreme sl and can't proper airflow threw defrost and i have hardly anything coming front vents if i switch it replaced actuator and still nothing could it be voltage issue to actuators been when testing i barely see them move maybe a mm or two and dont hear door fully shut but if i take the actuator off i can manual close door but still have no air threw vents n no improved air threw defrost is there more then two actuators on the car?

driver side is the recirculate and passenger is blend door one? is that correct

 

any help would be great, it has me stumped on

[pshojo]

I had issues with blend doors due to vacuum hose that had hole. The hose was near the battery on the strut tower side. Look at those hoses and tight points 

[Schurkey]

My '92 and '93 Luminas both had issues with the vacuum hose leading to the spherical vacuum reservoir just ahead of the LF wheel, below the battery.  The hose connects to the main vacuum supply somewhere around the master cylinder.

But the problems were not so much with the blend (hot/cold) doors, but with the defrost/floor heat, and with the cruise control.  When the hard, brittle plastic vacuum hose would outright break, I'd have no cruise control, and the HVAC would switch to defrost.  However, more-minor leaks in that system would allow the cruise control to work but to lose speed over time; and to switch to defrost under acceleration then back to floor heat at steady speed.

A fair amount of that brittle, hard-plastic tubing has been replaced with ordinary rubber vacuum hose of the appropriate diameter.

Edited April 17, 2023 by Schurkey