Another heater problem, 94 LeSabre

I have a very similar but opposite problem to the recent 97 heater problem. My AC blows cold on the drivers side, but HOT on the passenger side. I have a black arm that comes out and is attached to the threaded rod. It was un attached, but I attached it following the other instuctions but without success. What else can I try?
I can't complain too much the car has 265,000 miles on it, but I would like to keep it going.
I forgot to mention that the arm and the threaded rod move when I change the temperature setting.

did you try and leave it diconected and move it manuely to make sure you have it sinked with the system disconect it turn of the system then re connect it were it end up door closed or open you may have to play with it

I solved part of the problem. The black arm I referred to was on the bottom of the box. When I pulled out the glovebox, I found the white arm. It pays to follow instructions. The white arm does not move when disconnected. My next step is to go to the junk yark and try to replace the upper motor.

that should take care of your troubles i had the same issue on my 92 lasaber