OK so what broke?
 

OK guys help me out with this one. My 05 Silverado started blowing out hot air on any setting (vent, A/C, or otherwise). It did it after I turned off the AC, cilmate selector was never moved off the coldest setting. So I was thinking that a damper between the selector and the heatercore is broken. Am I on the right track?

Good thing it is only going to be 90 and humid today and I have an hour ride home in traffic. :banghead:

It's possible the blend door stopped working. Or the AC stopped working.

Easy thing to do is check the pressure in the ac system and make sure that is in range. Make sure your ac clutch is engaging (clicking noise). If everything checks out there i would investigate the blend door or something along those lines.

The AC is fine. But even when I have the vent only on the coldest setting I have heated air bolowing out. It has to be something with the climate control not shutting a damper to the heater core. Right?

as long as the ac is working (are the evaporator lines cold with the ac on?) I vote blend door. It probably has a motor that burned out. Go prowl around fullsizechevy.com

Or the resistor in the climate control that operates the blend door shorted.

Absolutely, anything involved in blend door movement.

if the hvac system is still activated by vac lines like they are on my s10, see if you can check to see if one popped off or came loose off a connection. one came off on mine before and allowed hot air out of the floor vent constantly. i was able to acces my lines from the glove box, not sure if you will have the same setup.

Thanks guys!