I have a 03 tahoe lt with the dual electric climate controls. The drivers side blows both cold and hot air but the passenger blows just hot all the time. This just started this week and I checked all fuses and relays. Has anyone had this problem before or can lead me into the direction of fixing this as this is the wifes vehicle. Thanks in advance.

 

Blend door actuator failures are very common, you could try re-setting the system by doing the "re-park" procedure, and if that doesn't work you'll probably have to replace a blend door actuator. Search this section for both "re-park procedure" and "blend door actuator" and you should find a bunch of useful info