I have a 2000 Blazer LS. My heat is not coming through whenever I turn my **** to heat. It is getting pretty cold down here and need it fixed. It isnt my heater core either. I dont know what else it could be. Any help would be great.

 

Where does it blow from, does it change if you turn the dial to another position?
Could be the blend door or more commonly a vacuum leak in the system.

<edit> Have you searched for this or anything close to this?
I'd bet not because heater issues have been covered so much the cows just haven't come home, they've gone to butcher & their grandson cows have came home lol.