Blend Door Actuator

Replace the HVAC blend door actuator on a 2005 Dodge Viper, requiring removal of the passenger side lower dash panel and glove box to access the actuator mounted on the HVAC housing.

Warnings

Tools required

Parts

• Blend door actuator × 1 — Mopar 68037477AA or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable and wait 2 minutes
3. Allow HVAC system to reach ambient temperature if vehicle was recently operated
4. Set front seats to their rearmost position for improved access to lower dash area

Procedure

1. 1

   Remove Passenger Side Lower Dash Panel
   Locate the lower dash panel below the glove box on the passenger side. Remove the screws securing the lower panel (verify exact count, size, and location against the 2005 Viper service manual). Gently pull the panel away from the dash to disengage any remaining clips. Disconnect any electrical connectors for courtesy lights if equipped. Set the panel aside.
2. 2

   Remove Glove Box Assembly
   Open the glove box fully. Remove the glove box door stop arms on each side by pressing them inward to disengage from the dash. Remove the fasteners securing the glove box assembly to the dash structure (verify exact count, size, and location against the 2005 Viper service manual). Carefully pull the glove box assembly forward and disconnect the light connector if present. Remove the glove box assembly completely.
3. 3

   Access HVAC Housing and Locate Actuator
   With the glove box removed, use a flashlight to inspect the HVAC housing behind the dash. The blend door actuator is mounted on the HVAC housing, typically on the right side of the housing behind where the glove box was located. It is a small rectangular motor with a plastic gear shaft and an electrical connector. Identify the actuator mounting screws and electrical connector location before proceeding.
4. 4

   Disconnect Actuator Electrical Connector
   Locate the electrical connector on the blend door actuator. Press the locking tab on the connector and carefully pull it straight off the actuator. Do not pull on the wiring harness itself. If access is tight, use a flathead screwdriver to carefully depress the locking tab while pulling the connector.
5. 5

   Remove Actuator Mounting Screws
   Remove the screws securing the blend door actuator to the HVAC housing (verify exact count against the 2005 Viper service manual, commonly 2 to 3 screws). Note the orientation of the actuator and the position of the drive shaft relative to the blend door linkage before removal. Carefully pull the actuator away from the housing, disengaging the drive shaft from the blend door linkage.
6. 6

   Inspect Blend Door Operation
   With the actuator removed, use a flashlight to inspect the blend door linkage and door itself through the actuator mounting hole. Manually rotate the blend door shaft to verify the door moves freely through its full range of motion without binding. Check for broken linkage arms or door hinges. If the door binds or is damaged, further HVAC housing disassembly may be required.
7. 7

   Install New Blend Door Actuator
   Position the new blend door actuator near the mounting location. Align the actuator drive shaft with the blend door linkage shaft. The actuator should slide onto the linkage shaft without force. If resistance is felt, verify the actuator is in the correct calibration position. Once aligned, press the actuator firmly against the HVAC housing. Install the mounting screws and tighten snugly by hand (these small screws thread into plastic housing; do not over-torque — verify any published spec in the service manual).
   Torque spec

   Actuator Screws3 Nm (2 lb-ft)
8. 8

   Reconnect Actuator Electrical Connector
   Connect the electrical connector to the new blend door actuator. Press firmly until you hear and feel the locking tab engage. Gently tug on the connector to verify it is fully seated and locked.
9. 9

   Reinstall Glove Box Assembly
   Reconnect the glove box light connector if equipped. Position the glove box assembly into the dash opening and align the mounting holes. Install the fasteners securing the glove box to the dash structure and tighten securely. Reinstall the glove box door stop arms by pressing them into their mounting points on each side.
10. 10

    Reinstall Passenger Side Lower Dash Panel
    Reconnect any electrical connectors for courtesy lights if equipped. Position the lower dash panel into place, engaging any alignment clips. Install the screws securing the panel to the dash and tighten securely. Verify all edges of the panel are properly seated and flush with adjacent trim.
11. 11

    Reconnect Battery and Calibrate System
    Reconnect the negative battery cable. Turn the ignition to the ON position without starting the engine. Set the HVAC controls to maximum cold, then wait 10 seconds. Set the controls to maximum hot, then wait 10 seconds. Verify HVAC control type for this vehicle; on manual systems the actuator does not perform an automatic self-calibration and may only require simple range verification by cycling temperature controls.

Reassembly

1. All fasteners should be tightened to their specified torque values where applicable
2. Verify all electrical connectors are fully seated with locking tabs engaged
3. Ensure all trim panels and the glove box are properly aligned and secured before testing

Verification

• Start the engine and allow HVAC system to operate
• Test temperature control by setting to maximum cold and verifying cold air output from vents
• Test temperature control by setting to maximum hot and verifying hot air output from vents
• Slowly adjust temperature control from cold to hot and verify smooth transition with no clicking or binding sounds from the actuator
• Verify no air leaks or unusual noises from the dash area during HVAC operation
• Confirm all dash panels and glove box are secure with no rattles

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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