I have a '98 grand voyager with dual air control. The drivers side does not
blow heat.The passenger side seems to work fine.One of the few shops in
town suggests it may be the air control module gone bad costing
around$400.I have done the following:1.Changed the Thermostat. 2.Performed
the calibration test, All seems to work fine, actually blew hot air during
the test. 3.Checked for heated hoses in and out of heater coil, both hot.
4.Flushed radiator, but during all 3 drainings I only got about 7 quarts
of fluid out instead of 13 from all the books. 5.I removed the cover under
the drivers side dash and both heater core tubes are extremely hot, but
when I work the lever from hot to cold the little geared wheel does not
seem go all the way around.The square shaft does turn more than the gear.
The air conditioner works great!