Besides checking the thermostat (replaced) why is my Jeep Grand Cherokee blowing cold air instead of warm or hot when I turn the heater on.:confused:

Could the heater core or lines have air trapped in it or be plugged, preventing the flow of hot coolant from going through it?

Besides checking the thermostat (replaced) why is my Jeep Grand Cherokee blowing cold air instead of warm or hot when I turn the heater on.:confused:
There may be a restriction in the heater core preventing hot engine coolant from flowing freely. Do both heater hoses get hot?

It sounds like the blower motor is working but cold air only comes out. I wonder if a vent or door of some kind is stuck not allowing the warm air to go where you want it. Is there any vent type doors that would change or close off when using regular vents or air conditioning that could be stuck to cause the problem?

Other people have had problems with the actuator or control switches not functioning properly with their Jeep Cherokee's. Sounds like it can a very expensive problem if you have dealer fix it...

Maybe this link will help?

AC/Heating problems in 2002 Jeep Grand Cherokee - CNET Car Tech Forums (http://forums.cnet.com/5208-7811_102-0.html?forumID=78&threadID=257092&messageID=2544067)