Chrysler Repair: Heater working sporadicaly, sporadic intervals, temp guage

Question
Heat is blowing refrigerated air, cooler than outside temp, while the engine temp gauge is showing higher than normal temp. The system will rattle and then heater will put out cool air for 2-3 minutes. The temp guage will lower to normal range and the heat will stop blow cold air. The process will continue to repeat at sporadic intervals. The engine temp never gets lower than 200.
Fluid levels are normal. 2WD 5.2L V8

Answer
Hi Pat,
This sounds like a truck or full-size van because of the engine size, which I don't have manuals for. But the design of all the heater/ac systems use a mechanical air diversion door to send the ventilation air through the heater coil or through the ac coil or a mix to produce intermediate temps. The ac coil though should not be cold unless you have it on defrost, otherwise the ac compressor should not be activated if you have simply selected for heat (not windshield defrost). So it depends upon how that diversion door is moved (electrically or mechanically by a cable) as to why you have this variation and a lack of heat. So check the temp control lever of the ac/heater control panel to see how it works and look underneath the dash to see if you can see anything move when you change the temp lever. That is about all I can suggest.
Roland