I have a 2003 quad cab 1500. My air vents no longer switch to defrost or floor. They just stay on the front panel vents all the time no matter which setting I put it on. I think it just stopped changing one day. Also, it just barely gets warm on the driver's side, but it still will blow hot on the passenger side. Does anyone no what might be causing these issues? THANKS!

 

sounds like a stuck vent door. my bodyshop guy worked on my vent issues in my 94 New Yorker

 

Sounds like a broken blend door. A lot of people around here have had problems with that. Do a search for blend door and you should see lots of posts about it. Basically what happens is the trap door that switches where the air comes out breaks and gets stuck in one position.