I have a '99 Buick Regal that is doing the same thing. I have heard that there is a servo motor under the dash the controls the vent door and that this may be the problem. I have not been able to find out much more. There is a vacuum box under the dash and it is working fine. The control system seems to be working fine too.
I have the same problem with a 93 Buick Park Avenue it seems to happen whenever the battery goes dead from leaving the lights on or some other cause. Also have seen threads about this when battery is replaced. I usually only notice it when it is cold outside. One side is hot and one side is cold? dual climate control? Also what happens is sometimes if not all the time the temp guage might flash on the control panel, that is what is moving the damper. If you shut off the car and turn back on the car it will blow hot on both sides and then the damper moves again. Seems to be a common problem and there was a reset I had that would sometimes by hitting buttons give hot air but what it does it moves the dampers back where they are supposed to be but then it went out of sync again and cleared up in the summer for some reason, but left the lights on and now it is doing it again. Leaving the lights on and battery going dead did it for me? Anyone else?
because someone was fiddling with the passenger climate control and now that baffle has stuck in the cold position . I had a 1997 buick lesabre which had the climate control functioning until a friend started adjusting it a few times then it became stuck in the cold position but only for the passenger side It is likely a mechanical bind in the baffle .
Make sure refrigerant is fully charged. Does it have dual climate control? Perhaps passenger side sensor is not working properly
howyou can replace the passenger side mirror for a 2007 Buick lacrosse?
2004 Buick Rainier - Radio Fuse is #41 in the Fuse Block, under the drivers side rear passenger seat . . .
You can find the 2001 Buick Century Oddie control module on the passenger side firewall. The body control module will be near the bottom of the firewall.
Door in vent box is not opening for the drivers side. Probably a bad vacuum line to the diaghram. If there is not a separate door than single door is not opening all the way. Also check for obstruction in the vent
Unfortunately only the drivers side has an interior control joystick. The right side is manual and must be adjusted the old fashioned way.
it is in you ecu witch should be under drivers seat, if not it is under passenger side dash
because u r gangsta
Under the dash on the passenger side below govebox
Had the same problem. In my case it was the actuator motor inside of the panel in the passenger footwell. Check to see if the flap is binding or it is the actuator motor itself.