Air conditioner control problem

I have a 2001 ls that has a problem with the temperature control. The driver side duct will suddenly become hot and the passenger side will remain cool. The dealer has checked the refrigerant charge and the a/c codes do not shoe any thing. Has anyone run accross this problem that could help me communicate this to the dealer as to what to check. Seems like a control problem with the ducts and or thermometer.
Thanks

I have a 2001 ls that has a problem with the temperature control. The driver side duct will suddenly become hot and the passenger side will remain cool. The dealer has checked the refrigerant charge and the a/c codes do not shoe any thing. Has anyone run accross this problem that could help me communicate this to the dealer as to what to check. Seems like a control problem with the ducts and or thermometer.
Thanks

Yes - several of us have had this issue - it's a problem with the blender valve. high $cost$ to repair since you have to pull most of the dash out.

Thankfully - most of the issue seem to go away after the next cold start - not to return.

I wouldn't rush to repair this item. Try to wait it out. I suggest closing the vents on the drivers side so you don' t get hot a pissed at the same time. It may invoke road rage.