2000 Chrysler Cirrus

First feel the upper radiator hose after the engine is warmed up. It should be too hot to hold onto for very long. If it's cool, suspect the thermostat. If it is hot, feel the heater hoses. If they are also too hot to hold onto for long, the heater core is fine and the mode doors, actuators, and controller in the heater box are suspect.

If you still need to flush the heater core, follow the lower radiator hose to the metal tube on the front of the engine. There is a smaller tube attached to it that leads to one of the heater hoses. The rubber hose is only a few inches long. That's a good place to take it apart. The other heater hose is a metal tube right above the one you just took apart. That one also has a rubber hose to the left that's a few inches long. Take it apart there, then run water through them from a garden hose.

Those metal tubes turn into rubber hoses again when they go into the firewall, but they're real hard to access back there.