I have a 2000 GS300 that I am having a problem with the front windshield defroster. It works on the drivers side (blowing warm air when set for defrost) but blows ice cold air from the passenger side windshield/defrost vents regardless of temp settings, all other heating and ac functions operate properly PS: I have owned this car for 8 trouble free years. please help thank you!

 

Sounds like it might be an issue with the AC blend doors.