This unit plays a crucial role in regulating the temperature inside your vehicle, allowing you to easily switch between heating and cooling settings. It’s designed to be user-friendly, ensuring that drivers can quickly set their desired climate settings.

Over time, climate control units may fail due to wear and tear, poor connections, or electrical issues. Regular checks and timely replacements can help maintain optimal performance and prevent discomfort while driving.

Technical Information

• Manufacturer: PSA
• Model: Citroën C4
• Product Codes: 9658084577, 6451SN
• Additional Numbers: 6451SP

High-quality manual HVAC control unit manufactured by BEHR, commonly referenced under codes B5RF, 6451VK and B9642. This climate control panel is intended for mechanics and experienced DIYers who need a reliable replacement part for Citroën C4 and Peugeot 307 vehicles. The unit provides intuitive mechanical control of temperature, fan speed and air distribution, with robust rotary controls and sliders designed for everyday use. Often searched by product codes B5RF and 6451VK, this part helps restore full HVAC functionality when original controls become worn, sticky or mechanically damaged.

Technical Information

Manufacturer: BEHR

Model: Citroën C4; Peugeot 307

Product Codes: B5RF; 6451VK

Other Numbers: 6451.VK; 6451VK; B9642

Function And Application

This mechanical control module operates the vehicle heater and air conditioning system functions such as temperature selection, blower speed, air distribution (dash/foot/windshield) and recirculation. It translates the driver’s inputs into movement of internal linkages, cables or electrical signals (depending on the vehicle’s configuration) to actuate blend doors and blower controls. Designed as a direct replacement for the original unit used in many Citroën C4 and Peugeot 307 models, it restores tactile control and accurate regulation of cabin climate.

How To Replace

Replacement is straightforward for a trained mechanic or competent DIYer with basic hand tools. Typical steps:

• Remove the center dash trim surrounding the control panel to access fasteners.
• Unscrew the retaining screws and gently pull the unit forward to access connectors and control cables.
• Unplug the electrical connector(s) and release any Bowden cables or linkages, noting their routing and attachment points.
• Install the new control unit by reconnecting cables and connectors in the original positions, secure with screws and refit the trim.
• Check all functions (fan speeds, temperature adjustment, recirculation and air distribution) before final reassembly to ensure correct operation.

Installation Recommendations

• Work methodically and keep small screws and clips organized to avoid damage or loss.
• Before disconnecting electrical connectors, make sure ignition is off and follow safe workshop practices.
• When detaching or reattaching Bowden cables, do so carefully to avoid kinking or incorrect routing which can cause poor control response.
• Verify fuses and blower resistor if fan speeds are intermittent or non-functional, as multiple components can cause similar symptoms.

Why This Part Fails Most Often

Common failure modes for manual HVAC control units include mechanical wear of knobs and internal linkages, degradation of plastic gears or sliders, and contamination from dust, dirt or spilled liquids that cause sticky or intermittent controls. Prolonged sun exposure can embrittle plastic components, while repeated use over many years accelerates mechanical wear. Electrical contacts for fan speed or switch functions may also become corroded or worn, leading to loss of specific blower speeds or unreliable operation.

Practical Tips

When diagnosing HVAC faults, inspect switches, cables and connectors before replacing the control unit. Symptoms such as no blower at any speed, only certain speeds working, or stuck temperature sliders can point to either the control unit or related components (resistor pack, blower motor, cables). Replacing the control unit typically restores full manual control when the original panel is mechanically damaged or worn.

The replacement of the air conditioning control is straightforward, making it suitable for both professional mechanics and automotive DIY enthusiasts. Typically, this unit can wear out due to prolonged exposure to heat and frequent use, leading to potential malfunctions in climate control.

With the original Behr design, this product maintains the integrity and functionality expected from Citroën components, making it a reliable choice for your vehicle’s air conditioning system.

Technical Information

• Manufacturer: Behr
• Model: B5CH
• Product Codes: H5754, 6451VJ
• Other Numbers: Not applicable

Ensure your Citroën C4 remains equipped with the best air conditioning control solutions available, optimizing not just comfort levels but also vehicle performance.