Blower Motor Control Module

Remove and replace the blower motor control module located in the HVAC system housing, which regulates cabin climate control fan speed.

Warnings

Tools required

Parts

• Blower motor control module × 1 — Use OEM specification
• HVAC module seal (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and apply parking brake.
2. Turn ignition off and remove key.
3. Open hood and disconnect negative battery terminal using 10mm socket. Secure cable away from battery post.
4. Wait at least 10 minutes for airbag system capacitors to discharge.
5. Ensure cabin temperature is comfortable, as HVAC will be inoperative during repair.

Procedure

1. 1

   Access lower passenger footwell
   Move passenger seat fully rearward and recline backrest to maximize working space. The blower motor control module is mounted on the HVAC housing behind the lower dash. Verify the exact access side (driver vs passenger footwell) against Aston Martin DB9 service documentation for this vehicle's LHD/RHD configuration before beginning disassembly. Move the passenger seat fully rearward and recline the backrest to maximize working space.vice documentation for this VIN before beginning disassembly. Note: The blower motor control module is located in the HVAC housing behind the lower dash; verify exact side (driver or passenger) against Aston Martin DB9 service documentation before beginning.
2. 2

   Remove lower dash trim panel
   Locate and remove the lower passenger side dash trim panel (kick panel). This panel is typically secured by plastic push clips and Torx fasteners. Identify visible Torx fasteners and remove them using appropriate Torx driver. Gently pull the panel away from the dash structure, releasing push clips. Work carefully to avoid breaking clips.
3. 3

   Remove passenger side lower insulator panel
   With the kick panel removed, locate the sound insulation panel behind it. Remove Torx fasteners securing this panel to the dash structure. The panel may also have integrated clips along the upper edge. Carefully lower and remove the insulator panel to expose the HVAC housing.
4. 4

   Locate blower motor control module
   Using a flashlight, identify the blower motor control module mounted to the side of the HVAC housing. The module is a rectangular electronic component with a wiring harness connector and cooling fins or heat sink. It will be positioned near the blower motor assembly itself, typically on the lower front section of the HVAC housing.
5. 5

   Disconnect module electrical connector
   Locate the wiring harness connector attached to the blower motor control module. Identify the connector's release type (locking tab or slide-lock) by inspection, depress/release it accordingly, and carefully pull the connector straight away from the module. Do not pull on wires; grasp the connector body. Note: Press the locking tab or slide the release mechanism (confirm the exact connector style for this module) and carefully pull the connector straight away from the module.
6. 6

   Remove module mounting fasteners
   Remove the mounting fasteners securing the blower motor control module to the HVAC housing. Verify fastener type (Torx screw, standard screw, or retaining clip) against Aston Martin DB9 documentation. Note the exact position and orientation of the module for installation reference. Note: Module Mounting Bolts — torque value to be verified against Aston Martin service data (do not overtighten into plastic HVAC housing). — torque value to be verified against Aston Martin service data (do not overtighten into plastic HVAC housing).
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
7. 7

   Extract blower motor control module
   Carefully pull the module away from the HVAC housing. The module may have a gasket or thermal interface pad between it and the housing. If present, inspect the seal for damage and note its orientation for reinstallation.
8. 8

   Install new blower motor control module
   Position the new blower motor control module with any gasket or thermal pad properly aligned. Ensure the module is oriented correctly to match the connector position and mounting hole alignment. Insert the module into position against the HVAC housing.
9. 9

   Install module mounting fasteners
   Install the mounting bolts and tighten to the manufacturer-specified value (typically a low in-lb figure for plastic-housing fasteners); if no spec is available, tighten hand-snug only to avoid stripping the plastic threads. Do not overtighten, as this can damage the module housing or the plastic HVAC housing threads.
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
10. 10

    Reconnect electrical connector
    Align the wiring harness connector with the module terminal and press firmly until the locking mechanism clicks into place. Verify the connection is fully seated and secure.
11. 11

    Reinstall insulator and trim panels
    Reinstall the lower insulator panel, securing with Torx fasteners and ensuring any clips are properly engaged. Then reinstall the kick panel, pressing firmly to engage all push clips and installing any Torx fasteners.
12. 12

    Reconnect battery
    Return to the battery location (in the boot/trunk on this vehicle) and reconnect the negative battery terminal. Tighten the terminal clamp bolt to the manufacturer-specified value (verify spec; terminal clamp bolts are commonly a low value — do not overtighten).nal clamp bolts); verify battery location (engine bay vs. boot) for this vehicle. Note: Return to the battery location (trunk/boot on this vehicle) and reconnect the negative battery terminal. Tighten the terminal bolt to specification.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Ensure all trim panels are fully seated with no gaps or misalignment.
2. Verify all Torx fasteners have been reinstalled in trim panels.
3. Return passenger seat to desired position.

Verification

• Turn ignition to ON position (engine off) and activate the HVAC system.
• Test all blower motor speed settings from lowest to highest to verify smooth operation at each level.
• Listen for abnormal noises from the blower motor or control module.
• Verify airflow changes appropriately with each fan speed selection.
• Test automatic climate control functions if equipped to ensure proper module communication.
• Check for any warning lights or HVAC fault messages on the instrument cluster.

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