Frustrated. I have a 2015 Dodge journey SE 2.4 I have no heat coming out of my system I have flushed radiator I have changed the thermostat I have changed the main actuator heat and cold door I will get heat for a second and then it goes cold. Can somebody help me and tell me what I can do next? I do my own work I do not take to a mechanic so if somebody can help me on what to do next that I can do myself please let me know. I live in a cold climate we get snow and I need my heat.