Temp control issues

My 99 park avenue has cold air blowing out of all the drivers side ducts and warm air that is selected blowing out of the pass side ducts,has anyone else had this issue,I am thinking the module in the dash or perhaps a door under the dash is open.

My 95 PA has the same issue except backwards. The warm air comes out of the drivers side and cold out of the passenger side. On mine there are stoppers that hold the glove box in the open position. I have to release those and reach back in the dash and move an arm that is back there to close the doors. I am going to replace the motor for that soon and see if that help. Our generally only does it if the temp control goes to auto. for some reason that door opens back up and I have to shut it again. I think this is a rather common problem on these cars from what i have read. At least it is for the ones that have the dual climate control