Chrysler Repair: Heater control 2002 Sebring, drb iii, heater hoses

Question
I just purchased from an auction a 2002 Sebring.  Works great, yet heater is not functioning.  Assume some form of disconnect between dial on dash and what it controls.  Cooling system checks out fine, no apparent air bubble or lack of coolant to suggest a problem that way.  Is this a simple mechanical issue?

Answer
I was

Hi Jim,
Thanks for that report about the heater situation. Unfortunately I failed to note your address before opting to use the tab to send you a simple 'your are welcome' response. By doing so I now find that I cannot resurrect your message back to me. So please tell me again the mailing address and I will indeed send those pages about the blend door actuator.
Roland

Hi Jim,
The proximate temperature controller is called the blend door actuator. It is operated by the body control module which mediates between the control panel and several actuators on the air box itself. It can be tested by means of a Chrysler diagnostic machine called a Diagnostic Readout Box III. The alternative is to replace the blend door actuator and see if that fixes the problem. Before doing that you would be well-advised to touch the incoming and outgoing heater hoses at the fire wall to see their relative temperatures. If they are similar in temperature then you have good flow through the heater core and so the problem is indeed the blend door not being positioned so as to send more air through the heater core and less from by-passing it. That implies that the actuator is not properly positioning it.
If one hot is hot and the other relatively much cooler, then you have an impeded flow of coolant through the core of the heater which needs to be resolved.
I can xerox a couple of pages from my copy of the '03 manual so you could see which of the acturators is the one in question and then replace it if you want to try that approach rather than to pay a dealer to test it via the DRB III. If you want the pages send me you postal mailing address via a follow-up question.
Roland