Kind of at a loss here Started in the summer Heat was stuck on couldnt get Ac to run and couldnt switch it on the control panel. Not sure what the last tech did but somehow got AC to run now we have no heat... Replaced control Module Both lines are hot running into the back of the heater core the intake hose is definately hotter than the outlet. all the electrics seem to be working fine. replacing the thermostat today... Anybody have any other ideas as to why we would have AC but no Heat... It does blow warm but barely.
Just a wag. It might have a ' temperature door' that is not functioning.
Refering to the doors that are by the heater core? all the actuators seem to be functioning on the outside case that holds the heater core inside.
I'm not familiar with this machine. To my understanding the temperature blend door would be inside the evaporator/ heater core housing directing the airflow over the evaporator or heater core or both as required. Maybe get a look inside to see if that is working? You might want to confirm go flow through the heater core also.
if both lines are hot, and one is hotter than the other, then you have coolant circulating, and you have SOME air circulating. The blend door is a good place to check. The filter could be blocked up so you're not getting enough air flow through the heater core, and more around it. If the filter is missing, then the heater core will collect the chaff and dirt and block air flow there. I wouldn't bother replacing the thermostat unless the coolant isn't reaching 180 when working, check the head with a non contact thermometer.
25 (motor) moves 41 (door) to regulate heat output. Remove 25 (3 screws) and manually swing door. One way is full heat, the other is no heat. Motor (actuator) may be bad, door may be stuck, temperature sensor may be bad, bad controller, etc. But, heater core is always at engine temperature.
Also you may find a mouse nest in there. Have found on several excavators and bulldozers before. As someone said before all filters okay. Simon