I've got a 1994 Z28 Camaro LT1, the AC works fine but heater blows cold? Fan still cycles through different settings just no heat. Let me know what you guys think.

 

Once the engine is fully warmed up, feel the two hoses going to the heater. They both should be about as hot as the the radiator hoses. If they remain cool, then the heater core is clogged. If both are hot, then the temp control is not working, possible a broken or maladjusted control cable.