GM Service Manual Online
For 1990-2009 cars only

    Object Number: 473008  Size: SH
  1. Disconnect the mode control cable from the clip (2) and the door at the heater case.
  2. Set the mode lever to the VENT position.
  3. At the heater case, hold the door lever fully toward the rear end of the vehicle the cable to the clip.
  4. Inspect the mode lever for smooth operation.
  5. Ensure that the mode lever stops at the correct positions.