Heater blowing cold air: '00 lhs

QuestionEdit

i have a 2000 chysler lhs 3.5L with atc just replaced t/stat and coolant,bled system but still get cold air blowing from system first time for this problem

AnswerEdit

Hi Bob, I would first verify that you do have coolant flow through the HVAC heater core. Drive the car until it is warmed up, then compare the temperature "to touch" of the incoming and outgoing hoses that pass through the firewall from the engine to the heater core. They should feel about equally hot. If not, then you either have air trapped in the system or a heater core that is partially clogged. There is a detailed procedure for refilling the system so if you may not be aware of that let me know and I can tell you the details. If the that was done properly and still the hoses are quite different in temp then I would try back-flushing the heater core to improve the flow through. If the hoses support the idea that you have good flow through, then the likely cause of no heated air is that the blend door air actuator is not moving that door properly to get the desired mix of air that is cold and air that is hot. There is a self-diagnostic capability of the HVAC control head but its means of access depends upon whether you have the digital temp readout type of controller (called automatic temperature control), or a conventiinal control. Let me know which I then I can tell you how to run that diagnostic test. Roland