Carol Schaffer-Author

I put a new thermostat in my Jeep Grand Cherokee and it's warm heat but still doesn't get hot air. What can be wrong.

jeep58

I just flushed the heater core, take the hoses off and run your garden hose one side of the hose till you see clean water.

onew1ckedxj

This^^ and also make sure there is no air trapped in the cooling system as well.

dave1123

I don't know where you are, but sub-zero incoming air can make more heat at lower blower speeds. Just saying.

mauser1891

Hello Folks,

I just ordered a heater door actuator as my actuator was missing for some reason. It didn't bother me until just this month.
I also just acquired a heater resistor unit. My heating unit is a automatic temperature control (ATC).
I have hot water flowing through my system as I can feel it when I touch the housing.

Thank You,
mauser1891

dave1123

With the automatic climate control heater, you don't have a blower resistor. The blower speeds are controlled by the computer inside the unit. There is a pulse modulated relay where the blower resistor goes.

To Carol Schaffer, I'm having the same problem with my 2000 WJ. My heater core is clear, the steel pipe to the water pump is clear, the blend door is working and the hoses are getting hot. It just doesn't seem to be making heat the way it used to. About the only thing I haven't done is take the dash apart to see if there's debris in the air duct to the core. With mine, if you put it on recirculate, it'll melt your chest hair, but then the windshield fogs up without heat on it.

mauser1891

Hello Folks,

True the module is solid state, but it is referenced as a blower motor resistor.
I was merely suggesting a possible solution, and forgot the link to the part.

Thank You,
mauser1891