Mode Door Actuator

Replace the HVAC mode door actuator, which controls airflow direction (defrost, panel, floor vents) in the climate control system.

Warnings

Tools required

Parts

• HVAC mode door actuator × 1 — Mopar 68029719AA or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake.
2. Allow engine and HVAC system to cool completely.
3. Disconnect negative battery cable and wait 2 minutes.
4. Set steering wheel to straight-ahead position for maximum working clearance.

Procedure

1. 1

   Remove driver seat
   Slide the driver seat fully rearward. Locate the four seat mounting bolts securing the seat tracks to the floor (two front, two rear). Remove all four mounting bolts using a socket. Disconnect the seat belt buckle electrical connector if equipped. Carefully lift and remove the seat from the vehicle. This provides necessary access to the lower dash area in the confined Viper cockpit.
2. 2

   Remove lower dash trim panel
   Locate the lower dash trim panel below the steering column. Remove the panel fasteners (typically Phillips screws along the upper edge and push-pin clips along the lower perimeter). Gently pull the panel away from the dash, working around the edges with trim tools to release any remaining clips. Disconnect any electrical connectors present on the panel before fully removing it (verify which, if any, controls are mounted to this panel on the Viper).
3. 3

   Remove lower knee bolster
   With the lower trim panel removed, locate the knee bolster (reinforcement panel) above the pedal area. Remove the bolts securing the knee bolster to the dash structure. Carefully lower and remove the bolster to expose the HVAC plenum housing behind it.
4. 4

   Access HVAC plenum chamber
   Identify the HVAC plenum assembly located behind the center console area and below the dashboard. The mode door actuator is mounted on the HVAC plenum chamber; verify its exact location (driver or passenger side) against factory service data, as it dictates the correct access path. Use a flashlight to locate the actuator—it is a small electric motor with a gear mechanism, typically mounted with 2-3 screws and has a wiring harness connector.
5. 5

   Disconnect mode door actuator
   Locate the electrical connector on the mode door actuator. Press the locking tab and disconnect the harness connector from the actuator. Note the orientation of the actuator and the position of the drive gear relative to the mode door linkage before removal.
6. 6

   Remove actuator mounting fasteners
   Remove the mounting screws securing the actuator to the plenum housing. In the Viper application, access is extremely tight—work carefully to avoid dropping fasteners into the plenum or behind the dash. Once fasteners are removed, gently wiggle the actuator to disengage the drive gear from the mode door linkage shaft.
7. 7

   Remove mode door actuator
   Carefully extract the actuator from its mounting location. The tight working space may require rotating the actuator at an angle to clear surrounding ductwork and structural components. Inspect the mode door linkage shaft for damage or excessive wear.
8. 8

   Install new mode door actuator
   Position the new actuator so the drive gear aligns with the mode door linkage shaft. The actuator gear should engage fully with the linkage—you may need to manually rotate the gear slightly to achieve proper alignment. Seat the actuator flush against the plenum housing mounting surface.
9. 9

   Secure actuator and reconnect wiring
   Install the actuator mounting screws and tighten securely. Reconnect the electrical harness connector to the actuator, ensuring the locking tab clicks into place. Gently tug the connector to verify it is fully seated.
10. 10

    Test actuator operation
    Reconnect the negative battery cable temporarily. Turn the ignition to the ON position (engine off). Cycle through all HVAC mode settings (panel, bi-level, floor, defrost, mix) using the climate control interface. Listen for smooth actuator operation and verify that the mode selections change appropriately. If operation is erratic, recheck actuator gear engagement with the linkage. Disconnect battery again before final reassembly.
11. 11

    Reinstall knee bolster and lower trim
    Reinstall the knee bolster to the dash structure and secure with its mounting bolts. Reconnect any electrical connectors to switches or controls on the lower trim panel. Position the lower dash trim panel and secure with its screws and push the perimeter clips into place until fully seated.
12. 12

    Reinstall driver seat
    Reconnect the seat belt buckle connector if equipped. Carefully position the driver seat into the vehicle, aligning the seat track mounting holes with the floor mounts. Install all four seat mounting bolts and tighten to the manufacturer's specification (verify exact torque against factory service data before final tightening). Slide the seat forward and rearward to verify proper track operation.

Reassembly

1. Reconnect the negative battery cable.
2. Start the engine and allow HVAC system to reach operating temperature.
3. Verify all trim panels are securely fastened with no rattles or loose clips.
4. Adjust driver seat to preferred position and verify seat track security.

Verification

• With engine running, test all HVAC mode selections (panel, bi-level, floor, defrost) and confirm airflow direction changes appropriately for each setting.
• Listen for any abnormal clicking, grinding, or binding noises from the actuator during mode changes.
• Verify that airflow distribution matches the selected mode throughout the full temperature range (cold to hot).
• Confirm no air leaks or whistling sounds from the HVAC system during operation.

Related trouble codes on this vehicle

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