Thread: AC works but getting heat

My AC blows cool to warm air but when I pinch off one of the heater hoses my AC will work like it should. When the AC is turned on is there a valve in the coolant line to shut off flow to the heater? If not, I think I have a blend door problem.

How do I get to the blend door? I have a standard hvac system not dual zone in a 97 GP.