GMC Repair: temperature control, gmc yukon xl, gmc yukon xl denali

Question
I have a 2004 GMC Yukon XL Denali. In the front seats there are separate controls to control the temperature on the drivers side and the passenger side. Yesterday the air on the passenger side  started blowing only hot air. Even when the air conditioning is on. Could it be a blocked vent or a blown fuse?

Answer
Hi
It is a common issue with that HVAC system.
The best thing to do is take it to the dealership OR a repair shop that has GM reprogramming capibilities.
There is an updated program for the HVAC actuators so this does not happen.
The actuators will then need calibration, but it should do this on it's own.
Alot of times the problem will come and go, maybe one day it'll blow correct and a few days later, it will act up again. If that happens AFTER reprogramming, the temp. actuator will probabally need to be replaced.
You MAY also want to get the system scanned for codes.
That'll help in diagnosis of HVAC system. There are some wiring issues also with this system, but the symptoms are usually with te drivers side. You MAY want to have that checked, also.
Hope this helps.
Good Luck
Pawl