Welcome, I'm Chris (aka Moose). Experts aren't employees / agents of Just Answer. We are independent service providers using the Site to sell their Expert knowledge to Customers. I strive to provide EXCELLENT 5 STAR service, let me know what's needed from me so your pleased.
First thing I need you to do is get the engine to operating temp with the blower on high and the heat on full. While running carefully grab the upper radiator hose, it should be about 180 F now grab both heater core hoses on the firewall passenger side. Both should be about 160 F. If they are much colder then you have a restricted core or a stuck open thermostat or the water pump impeller fins are corroded and its not moving enough coolant. Let me know this test result.
If the hoses are hot then its likely the blend door actuator in the dash. To diagnose that after the coolant hose test result, I need to know if you have auto or manual climate control.
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