My van has manual heating and AC, driver and passenger zones, plus rear heat and AC. The driver's temperature control was not outputting blended air, only unheated air or maximum temperature air. Moving the driver's side heat control slider from cool to hot had no affect on the air temperature...
Have a 95 Plymouth Voyager that only rarely has heat.
•will occasionally have heat for a minute or two.
•temperature gauge will warm up some then goes dead
•may be unrelated but factory stereo stopped working around the same time
•has new thermostat
•testing seems that if the temp gauge begins...