Servo Valeo Citroën Peugeot F663746X.C 6447NL

Description

Heating servo motor for CITROEN C2, C3 and PEUGEOT 1007

Part description

The Valeo servo marked F663746X.C (PSA code 6447NL) is an electric servo motor used in the heating/air conditioning system. Its task is to control the dampers in the HVAC unit and thereby control the flow and mixing of air (eg temperature and direction of flow) according to the settings of the controllers. If the servo motor does not work properly, the heating or ventilation may react with a delay, irregularly, or the required mode may not be set.

This is a used part suitable for repair without unnecessary replacement of the entire unit – an ideal choice for mechanics and home repairers looking for a part by exact number.

Technical information

• Manufacturer: Valeo
• Model: Citroën C2, Citroën C3, Peugeot 1007
• Other numbers: 6447NL

Product codes

• Product codes: F663746X.C, 6447NL

Installation recommendations

Generally/typically for heater servomotors, the exact procedure and access to the part varies according to the specific car design and equipment. Below is a practical, safe procedure for replacing this type of part.

1) Before assembly (checks of used part)

• Compare the part numbers with the old part: F663746X.C and/or 6447NL.
• Check the match of the connector (shape, number of pins, locking) and fixing (spacing, orientation).
• Check that the shaft/driver is not damaged and can be turned smoothly (without binding).
• Visually check for cracks in the package, broken latches and the condition of the contacts in the connector (oxidation, bending).

2) Necessary tools and materials

• Basic set of screwdrivers and bits (according to the type of connecting material)
• Ratchet with attachments / possibly small tools for confined spaces
• Plastic pry bar for removing covers/linings
• Flashlight
• Electrical contact cleaner (recommended) and dry cloth

3) Step-by-step assembly procedure

1. Turn off the ignition and disconnect the battery for safety reasons.
2. Get access to the servo motor – typically after removing part of the covers/paneling in the dashboard area (depending on the design).
3. Before disassembly, take a photo of the position of the connector and wiring so that you don’t mess anything up during assembly.
4. Disconnect the electrical connector (disengage the latch, do not pull the cables).
5. Unfasten the servo motor and remove it carefully so as not to damage the driver/gearing.
6. Check the counter (lever/flap axis): not cracked, worn or blocked by debris.
7. Compare the old and new piece (orientation, connector, attachment). If everything matches, place the servo motor in the correct position.
8. Install the fasteners and tighten them evenly (without force to avoid cracking the plastic parts).
9. Connect the electrical connector and verify that it is properly secured.
10. Put back the removed covers/trims and check that there is no pinched wiring.
11. Connect the battery.
12. Turn on the ignition and perform a basic function check (changing temperature settings/flow modes) and observe the system response.

• 4) Post-assembly checks and functional test verification

  • Verify that heating/ventilation setting changes are smooth and repeatable.
  • Check that the connector does not come loose during operation and that the wiring does not touch any moving parts.
  • If the system does not respond correctly, recheck the seat of the servo on the follower and the condition of the flap abutment.

  5) The most common assembly mistakes + how to avoid them

  • Mismatched part (different number/connector): always compare F663746X.C / 6447NL and physical design.
  • Damage to the connector latch: unlock in the right direction, do not force it.
  • Incorrect seating on the driver: the servo must land without force; if it doesn’t work, check the position and counter.
  • Pulling the screws into the plastic: tighten with sensitivity so that the attachment does not crack.
  • Ignoring flap stutter: if the flap mechanics are stiff, the new servo can go quickly – remove the cause of the load first.

  Reasons why the part is damaged

  • Mechanical overload due to frozen or dirty dampers in the heating/air conditioning unit.
  • Wear of gears and internal parts of the servo motor after years of operation.
  • Voltage fluctuations or worse contact in the connector (oxidation, loose pins).
  • Moisture and dirt in the HVAC area, which can accelerate corrosion of the contacts or impair the operation of the mechanism.
  • Improper assembly/disassembly (broken attachment, damage to the connector, bad seating on the driver).