GM Service Manual Online
For 1990-2009 cars only

    Object Number: 345804  Size: SH
  1. Disconnect the mode control cable (2) from the clip and door at the heater case.
  2. Set the mode lever to the VENT position.
  3. At the heater case, push the door lever fully clockwise (forward) and affix the cable into position.
  4. Inspect the mode lever for smooth operation.
  5. Ensure that the mode lever stops at the proper positions.