Blower Motor Control Module

Replace the blower motor control module which regulates HVAC fan speed in the S65 AMG. Module is located in the passenger footwell behind trim panels.

Warnings

Tools required

Parts

• Blower motor control module × 1 — A2218702726 or equivalent
• Trim panel clips (if damaged) × 5 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn ignition off and remove key
3. Open hood and disconnect negative battery terminal, then positive terminal
4. Wait minimum 3 minutes for electrical system discharge
5. Move passenger seat fully rearward and raise to highest position for access
6. Ensure interior is well-lit for work in footwell area

Procedure

1. 1

   Remove passenger side footwell trim panel
   Locate the lower trim panel on the passenger side footwell. Remove T20 Torx screws securing the panel (typically 3-4 screws). Carefully release trim clips by pulling panel outward starting from bottom edge. Disconnect any courtesy light connectors if equipped. Set panel aside in safe location.
2. 2

   Access blower motor control module area
   With lower trim removed, locate the blower motor control module mounted on the HVAC housing behind the glove box area. You may need to remove the side insulation panel secured by push clips for better access. The module is a black rectangular unit with a multi-pin connector and cooling fins.
3. 3

   Disconnect electrical connector from module
   Locate the large multi-pin electrical connector on the blower motor control module. Press the locking tab on the connector while pulling straight out. Do not twist or rock the connector excessively. If connector is tight, use electrical contact cleaner to clean around the seal and allow to dry before attempting removal again.
   ⚠Connector locking tabs are brittle on older vehicles; apply gentle pressure only to avoid breakage
4. 4

   Remove ground strap connection
   Locate the ground strap bolt connecting the module to the vehicle chassis. Use 8mm socket to remove the ground strap bolt. Keep track of any washers or spacers under the bolt. Inspect ground contact surfaces for corrosion and clean if necessary with wire brush.
   Torque spec

   Ground Strap Bolts12 Nm (9 lb-ft)
5. 5

   Remove module mounting bolts
   Using 8mm socket, remove the two or three mounting bolts securing the blower motor control module to the HVAC housing. Support the module with one hand while removing the final bolt to prevent it from falling. Carefully extract the module from its mounting location, noting the orientation for installation.
   Torque spec

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

   Inspect mounting area and cooling airflow path
   With module removed, inspect the mounting surface for debris, water intrusion, or corrosion. Check that cooling air passages are clear of obstructions. Clean mounting surface with clean cloth. Verify that mounting bolt holes are clean and threads are in good condition.
7. 7

   Install new blower motor control module
   Position the new module in the same orientation as the original, aligning mounting holes. Insert and hand-thread all module mounting bolts to ensure proper alignment before tightening. Torque mounting bolts in a cross-pattern to specification to ensure even pressure distribution.
   ⚠Overtightening mounting bolts can crack the module housing; use torque wrench to exact specification
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
8. 8

   Reconnect ground strap
   Install ground strap to module or chassis ground point. Ensure contact surface is clean and free of paint or corrosion for optimal electrical connection. Install ground strap bolt with any original washers and torque to specification. Verify ground strap has no tension or stress that could cause fatigue over time.
   Torque spec

   Ground Strap Bolts12 Nm (9 lb-ft)
9. 9

   Connect electrical connector
   Apply small amount of dielectric grease to connector pins if desired for corrosion protection. Align electrical connector with module pins and push firmly until locking tab clicks into place. Gently tug on connector to verify it is fully seated and locked. Ensure no wires are pinched or stressed.
10. 10

    Reinstall trim panels and insulation
    Reinstall any insulation panels removed for access, ensuring push clips are fully seated. Position passenger footwell trim panel and align all mounting points. Install T20 Torx screws and tighten securely but do not overtighten plastic trim. Reconnect any courtesy light connectors. Verify all trim is flush and properly seated.
11. 11

    Reconnect battery and initialize system
    Reconnect positive battery terminal first, then negative terminal. Torque battery terminal bolts to specification. Turn ignition to position II (on) without starting engine. Allow climate control system to initialize for approximately 30 seconds. The blower motor may cycle through various speeds during initialization.
    ℹ️Do not overtighten battery terminals as this can damage terminal posts on this vehicle
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Ensure all trim panels are securely fastened and aligned properly
2. Return passenger seat to desired position
3. Verify no tools or parts were left in footwell area

Verification

• Start engine and test blower motor at all speed settings (1-5) to verify operation
• Verify blower motor responds smoothly to AUTO climate control mode speed changes
• Check that no warning lights are illuminated on instrument cluster related to climate control
• Test both driver and passenger temperature zone controls for proper response
• Use diagnostic scanner to verify no fault codes are stored in climate control system
• Listen for any unusual noises from blower motor area during operation
• Verify cabin air distribution changes properly between vent, floor, and defrost modes

Related trouble codes on this vehicle

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