Description
Heater Fan Regulator for Citroën AX, Saxo, Xantia, XM, Berlingo, Xsara, ZX and Peugeot 106, 405, 406, 605 and Partner
This heater fan regulator, referenced under part number 644178, is a direct-fit electrical component used to control blower motor speeds in a range of Citroën and Peugeot models. Designed for both professional workshops and DIY mechanics, the unit restores stepped fan control and smooth HVAC operation. Suitable search keywords: heater fan regulator, blower motor resistor, blower regulator 644178, Citroën fan regulator, Peugeot fan regulator.
The regulator replaces the original speed control module that modulates current to the blower motor and allows selection of multiple fan speeds from the dashboard. A failed regulator typically results in loss of some speed stages (often only the highest speed remains), intermittent operation or no blower function at lower speeds. Replacing the regulator is a common and cost-effective repair that brings back full ventilation control.
Technical Information
- Manufacturer: Stellantis (Citroën / Peugeot)
- Model: Citroën AX, Saxo, Xantia, XM, Berlingo, Xsara, ZX; Peugeot 106, 405, 406, 605, Partner
- Product Codes: 644178
- Additional Numbers: —
Recommended Installation
- Safety First: Disconnect the battery before starting work to avoid short circuits and to protect vehicle electronics.
- Location: The regulator is usually mounted on the heater box near the blower motor, accessed from the passenger footwell or behind the glove box depending on the model.
- Removal: Remove the glove box or lower trim panels if required, unplug the electrical connector, and remove retaining screws or clips holding the regulator to the housing.
- Replacement: Fit the new regulator in the same orientation, ensure the connector pins are clean and free of corrosion, then secure with original fasteners. Test all fan speeds before reassembling trim.
- Tip for Longevity: Clean connector contacts and apply a small amount of dielectric grease to prevent future corrosion. If the blower motor is noisy or draws excessive current, inspect or replace the motor as it can shorten the regulator’s life.
Most Common Failure Reasons
- Overheating Caused By High Current Draw: A worn or seized blower motor forces the regulator to dissipate more heat, leading to component failure.
- Corroded Or Poor Electrical Connections: Moisture and dirt on the connector cause increased resistance and localized heating.
- Contamination And Debris: Dust or debris inside the heater box can damage the resistor elements or impede cooling around the regulator.
- Age And Thermal Fatigue: Repeated heating and cooling cycles eventually degrade resistor tracks and solder joints.
This part is ideal for technicians and experienced DIYers looking for a reliable replacement for part number 644178. When fitting, verify clean connectors and consider checking the blower motor condition to avoid repeat failures.
