Hello, I was wondering if I can get some reference as to what can be going wrong in my 2002 Tahoe 5.3L. I just got it maybe 2 months ago and when I select the windshield defroster it stays blowing through the front vents and only the front vents. Any clue as to what it can be ? Thanks in advance!

 

my guess would be the part that directs the air flow is stuck.

 

Mode actuator or mode door is broken or stuck as stated by mountainmanjoe.

 

There are up to three electric actuators under the dash on these. I had one go bad on my 2005 and replaced it with a Dorman unit.

 

Thanks, will check it out !

 

Can someone please explain how I can check to see what the problem is?