Description
Heater servo motor BEHR or MES for Citroën and Peugeot vehicles.
Product Overview
This replacement heater servo motor (blend door actuator) is designed for Citroën and Peugeot HVAC systems and is commonly used to control airflow direction and temperature blend inside the heater/air-conditioning box. Identified frequently by part numbers such as 309370600 and 6447RX, this unit is compatible with multiple PSA models and is often searched by its product code. The compact electric motor with internal gearing provides the precise movement required to position flaps and doors in the climate control unit.
Technical Information
- Manufacturer: BEHR / MES
- Model: Citroën C4, Citroën C5 II, Citroën C6, Peugeot 307 (including 307 II)
- Product Codes: 309370600; 6447RX; CE CD AD 6447RX
- Other Numbers: Stellantis Citroën Peugeot references (see product codes above)
Function And Application
The servo motor actuates the internal flaps of the heater/AC box (blend doors and mode doors), enabling temperature regulation and directing airflow to windshield, face or feet vents. Proper operation is essential for accurate cabin temperature control and for preventing unwanted noises or improper vent selection.
How To Replace
Replacement is straightforward for a trained mechanic or experienced DIYer with basic tools. Typical procedure:
- Disconnect the vehicle battery before starting work to avoid short circuits.
- Access the HVAC box—on many PSA models the actuator is located behind the glovebox or under the passenger side of the dashboard.
- Remove the necessary trim or fasteners to expose the actuator, unplug the electrical connector and remove the mounting screws.
- Install the new actuator, secure with screws, reconnect the plug and test the function through the vehicle HVAC controls (verify all vent positions and temperature changes).
- Reassemble trim and reconnect the battery.
Installation Recommendations
- Perform installation in a dry, well-lit area and use the correct-size screwdrivers and torx bits to avoid rounding fasteners.
- After installation, cycle the climate controls through all modes to confirm full range of motion and quiet operation.
- If the actuator fails to respond or moves erratically, check wiring, connectors and ground points before replacing the second time.
- Keep the old part until correct operation is confirmed—it can help verify correct gearing or connector orientation.
Why It Usually Fails
- Worn or Stripped Plastic Gears: Most common cause—plastic gear teeth degrade over time and eventually slip or break, producing clicking noises and loss of movement.
- Motor Wear Or Burnout: Continuous use, heat exposure and age can cause the small DC motor to fail.
- Contaminants and Moisture: Dust, debris or condensation inside the heater box can accelerate wear or interfere with gear engagement.
- Electrical Issues: Corroded connectors or intermittent wiring can cause loss of power or erratic actuator behavior.
Typical Symptoms
- Clicking or grinding noise from the dash when changing modes or temperature.
- Inability to change airflow direction (stuck on one vent) or unstable cabin temperature control.
- Partial or no movement of vent doors despite HVAC command input.
Search And Identification Tip
Customers frequently search this part by reference numbers such as 309370600 or 6447RX. Use these codes when looking up fitment for specific PSA models to speed up identification.
