Heater problem

[codefreq]

1998 s10 zr2 with a hvac problem. It will blow air through the front vents and the defrost vents, but when in the floor position air will only come through the defrost vents.Also when the heat control knob is turned you can hear a creaking sound,like a door that needs oiled. Any info would be appreciated.

[Sparky2263]

The mode door motor is on the lh side of the box, close to the accel. pedal. You can view the linkage and may be able to see the problem while switching modes.

[baggedandcaddied]

those doors should be vaccum operated if i remember right maybe you have a vac line off or something in the way of the door, like sparky said the door is right by the pedal

[Sparky2263]

The later models have electrically operated motors. Think it started around 95-96.

[codefreq]

Thanks for the reply guys. Just had a chance to look under the dash(crappy weather and no garage).Found the mode door motor and it does operate on vacuum. There are two lines running to it(one red and one blue),only one of the lines has vacuum on it regardless of the switch setting. I disconnected the two lines and operated the lever manually and did not get any change from top vents to floor vents. The only logical conclusion I can come up with is that the door inside the case is disconnected. Any other thoughts? Thanks for all the input.