Last winter my heat worked amazing, it was blowing hot air before it was even halfway warmed up. Now I till not even blow warm air until it is completely warmed up and still takes another 20 min or so to blow warm-hot air. pulled apart blend door, and its not stuck but the actuator doesn't work. I'm assuming it is stuck in one position? all radiator hoses going to and from the firewall are hot and the heater core is fine. any ideas?