Heater problem, 2 left front vents on dash board are blowing ice cold air + right 2 vents are blowing hot air. is this a possible dial setting/button problem or actual haeater problem. heat was set @ 90 degrees + fan full blast. is there something I'm missing or does it need to go in for repair?

There is a separate button on the lower dash labeled RR HTR for the rear heater. If you do not engage the switch it will blow cold air.

Usually a sign of a faulty blend door under the dash.
The blend doors direct air thru the ac and heater core along with the upper and lower vents.

The vents may not be connected to the ducts under the dash, or a passage door may not be opening from the heater case to those vents. The doors may be cable operated or vacuum operated, or possibly operated from a body control module. Good luck.

You have a blend door issue under dash. Also possible blend door actuator motor may have failed. Try moving the mode select dial on control panel back and forth and listen for air sound change under dash at both sets of vents. If do not hear air flow change door is not moving.

check your air diverter doors, sounds like the door for heat is open, when a/c is selected the doors should move and close the heater off. the heater will over power the a/c. the door controller is located on the environmental station under the dash neat to the floor. the control is electronic and probably not functioning

common problem, check under dash by the gas pedal if control arms are muving went selecting from ac to heat cuz this it is the control for the vents to go from ac to heat and to defrost.

Had the same problem. believe it or not i changed the gas cap and got heat all around. something about pressure.

This is a blend door problem, this door diverts air either throgh the heater core or the AC accumulator core, it either provides hot, cold or a mixture or blend, this door is deep in the dash and in most cases the dash must be removed to service the little electric motor that operated the door.

wow...here it is spring and no one answered either of you? Is there a large volume of air when fan is on high? Where is it going? Or do you not hear anything from the fan? The 240 has an awesome heater. On high it would heat a small home! If no sound, your blower motor is dead assuming the fuse is good. If you hear the fan blowing, figure out where the air IS going. Note that the only way to turn the dash vents off is with the white Oreo dials. To defrost, only that button should be pressed in and dash vents off. Behind the dash switches there is a maze of short vacuum hoses. Often times, people monkey w/ these and reconnect them incorrectly. Haynes manual or Chilton's have proper diagrams. It could be that the vacuum hose coming from the manifold and entering the firewall is split on the under side and not visible, also.