GM Service Manual Online
For 1990-2009 cars only
  1. Disconnect the mode control cable from the clip and door at the heater case (1).
  2. Set the mode lever to VENT.

  3. Object Number: 354227  Size: SH
  4. At the heater case, push the door lever fully forward (counterclockwise) and affix the cable into position.
  5. Test the mode lever for smooth operation. Ensure that the lever stops at the proper positions.