I own a 98 Dodge Ram 1500 4X4 club cab. I have replaced the water pump and thermostat so the engine is heating to the right temp. The heater core gets too hot to touch by hand. The lever for the blend door is working and there is some difference in temp between cold & hot setting but not much. I can see the lever move and hear the door shut. The vent switch is working between all of the settings as well.
What else could this problem be?
thanks, Nate

You may have a partially clogged heater core.
Do both heater hoses get hot?
Normally the inlet hose will get very hot and the outlet hose will be somewhat cooler.
Check coolant level to make certain it is full, and when the entire system has cooled down, you can check for proper flow through the heater core.
Just take off both hoses leading to the heater core and try running a garden hose with moderate pressure through the core. Low flow will be apparent. Let us know...