Stuck hot air vent door?
 

OK, I have one main issue and a sub-issue: :) 1998 S70 GLT, 249k

Main issue: Heat always comes out the right side floor and dash vents when A/C is on. I get cold air on the left.

After taking out the glove compartment & right bolster (I am in the process of replacing a leaky heater core) I can see what looks like the a duct door pivot point (black rod with a square-ish hole in the end on the the side of the heater core box) move in slight increments when I move the ECC vent control, but it doesn't look like it moves very much and my suspicion is that the duct door that closes off the hot air is stuck or the servo motor is bad.

What I hoped to do was somehow manually move the door shut by turning the pivot (or helping the servo do it) to close off the hot air from the core. That would get me thru the summer anyway. Any experience with this, or perhaps exactly what the problem is would be appreciated. Searches revealed some comments about servo re-calibration, but I wasn't feelin' it. Valid?

Sub-issue: I thought I would compare the right-side pivot movement with the left side, but I can't figure out how to get the left knee bolster out. There were two nuts on the far left similar to those on the right bolster. I found two bolts (smaller head size than the nuts) in the center and on the right side of the (left) bolster, but I was leery about removing them without being sure of their purpose. If there are some left bolster instructions here, please point me in the right direction.

Sorry for the long post. Thanks in advance for any help!

Good thinking. The servos, if you can see them, then you can figure out how to make them blow cold. They may start working if you unhook them. if the damper is stuck you can check on that, and then you can decide how to reassemble. There are some adjustments available.