[murdog94]

If you had heat, and now dont, i have a few things. Are you still running the Dex Cool coolant (pink) if so there is a good chance that it has plugged your heater core. Also what temp does the motor get to? if it isnt getting to the normal range (190-210 degrees) then there is a chance that your Tstat is staying open and the coolant isnt getting warm enough to make the heater core work properly (yes the lines will be hot, but pressure, and actual temperature will be off enough to cause this)

 

[murdog94]

Yes you will want to back flush it (if that will do the trick it doesnt always work if the core is to far plugged) without the motor running and the hoses disconnected so you dont get any junk in the motor. As to Dexcool, that is the GM brand of coolant, and also what Dodge uses. It is Pink, the orange that you are talking about isnt the std coolant. So yes it sounds very much like your heater core is plugged up.
As to the coolant loss, how long did it take to leak that down?

 

[murdog94]

Then you will want to do the same thing as well.. it isnt uncommon for the heater cores to become plugged.

 

[murdog94]

Flush the entire system, and replace it with good old green coolant. (pink/orange it all depends on how you percieve the color i guess) anyhow get that dex crap out of there ASAP! and put in plain old green coolant. Dex Cool eats the gaskets in the motor as well.