We just replaced the thermostat and there isn't any heat at all. There was a bit of heat before the thermostat was replaced. The air conditioning does work.

 

Compare the temp difference between the 2 heater hoses where they go into the core. (don't grab them and burn yourself...use a thermometer)


If your gauge is at normal temp then you have a dirty core or a blend door issue inside. Make sure the cooling system is bled of all air. Another possibility is that your temp sensor is reading high and the fans are running too long.

 

Can you hear the blend doors operate as you change the temperature setting?
I spent hours trying to pin down my blend door problem on my Ram, then found that it was just low on antifreeze after a new rad install a month previous.....