If your heater hoses are hot, then your heater isn't plugged. If the inbound is but the outbound hose is cold you've got a heater core issue.
I would guess your blend door system isn't functioning, or you've got a vacum leak or leakdown if your vacum filter/check valve is bad. That valve is in the engine compartment on the back pass side, usually by the valve cover with a mess of other lines.
Try googling dodge ram blend door.