The FAURECIA seat heater relay is a direct replacement for a range of Citroën and Peugeot models and is frequently searched by part number (9638053380, 8904WC, 8906GR, 6545YN, FAURECIA 9445536). Designed to switch the high current required by seat heating elements, this relay ensures reliable operation of passenger and driver heated seats. Ideal for professional workshops and DIY mechanics, the unit restores proper seat heating function when the original relay becomes intermittent or fails entirely.

Key Benefits

• Direct fit for multiple Citroën and Peugeot models — simplifies sourcing by part number.
• Restores consistent heating performance and removes intermittent faults caused by worn relay contacts.
• Economical and quick replacement that eliminates diagnostics tied to heating element or thermostat faults.

How It Works And Typical Symptoms

The relay controls electrical power to the seat heating elements, acting as a high-current switch operated by a low-current control signal from the vehicle’s heater switch/module. Common symptoms of a failing relay include no heating, intermittent heating, heating that only works on one seat, or heating that cycles unpredictably. In many cases, dashboard switches and fuses are OK, pointing the fault to the relay.

Installation Recommendation

Basic replacement steps for a competent mechanic or experienced DIYer:

• Disconnect the vehicle battery before starting work to avoid short circuits and protect vehicle electronics.
• Locate the relay — it may be in a dedicated interior fuse/relay box, under the seat, or integrated into a module depending on model year and equipment.
• Remove any trim or fasteners necessary to access the relay socket, unplug the wiring connector, and pull out the faulty relay.
• Install the replacement relay by plugging it into the correct socket, secure any removed trim, and reconnect the battery.
• Verify seat heating operation and check for error codes if the vehicle displays related warnings.

Common Failure Causes

• Contact Wear And Pitting: Repeated switching of high current loads can erode relay contacts, causing higher resistance or complete failure.
• Corrosion Or Moisture Ingress: Water or humidity entering the relay housing or connector causes poor contact and intermittent operation.
• Overload Or Short Circuit: Faults in the seat heating element or wiring can overload the relay, leading to premature failure.
• Thermal Cycling: Frequent heating and cooling cycles accelerate material fatigue in internal components.

Technical Information

• Manufacturer: Faurecia
• Model: Citroën / Peugeot Seat Heater Relay
• Product Codes: 9638053380, 8904WC, 8906GR
• Other Numbers: 6545YN, FAURECIA 9445536, 9445536
• Compatible Models: Citroën C4 Picasso, Citroën C5, Citroën C5 X7, Citroën C8, Peugeot 207, Peugeot 3008 I, Peugeot 308, Peugeot 407, Peugeot 5008 I, Peugeot 807

Practical Tips

• When replacing the relay, inspect the mating connector and wiring for heat damage, corrosion or loose terminals and repair as needed to prevent repeat failures.
• If a relay failed due to a short in the seat element or wiring, replace or repair the faulty wiring/element before fitting a new relay.
• Keep replacement relays in stock by part number — technicians commonly search by the codes listed above for quick sourcing.

Why Choose This Part

This FAURECIA relay provides a cost-effective solution to restore seat heating functionality for many Citroën and Peugeot vehicles. With clear cross-reference part numbers and straightforward installation, it is well suited to both professional workshops and competent DIY repairs.

High-quality replacement seat heater relay designed for a wide range of Stellantis and allied platforms. Ideal for professional workshops and experienced DIYers, this relay restores reliable seat heating operation and is commonly searched by its part numbers (9673891680, 4539528, 6509ER). Durable design and direct-fit compatibility make it a practical spare for vehicles experiencing intermittent heating, blown fuses, or electrical faults related to seat comfort systems.

Key Features

• Direct replacement for OE references used on multiple Citroën, Peugeot and DS models.
• Manufactured by Kongsberg (reference 4539528) and cross-referenced with Stellantis numbers for quick identification.
• Restores proper switching of seat heating elements and protects wiring from repeated overloads caused by stuck contacts.
• Compact relay housing for easy integration into existing fuse/relay boxes or seat control modules.

Technical Information

• Manufacturer: Kongsberg
• Model: Seat Heater Relay / Seat Heating Relay
• Product Codes: 9673891680; 4539528; 6509ER
• Other Numbers: 4539528 | 6509er | 9673891680

Compatible Models (Typical Fitment)

Commonly fitted to a range of Citroën and Peugeot vehicles and some models from DS, Opel, Fiat and Toyota. Examples include:

• Citroën Berlingo III
• Citroën C3 III
• Citroën C5 (including C5 X7)
• Citroën C8
• Peugeot 308 (T9)
• Peugeot 5008 I
• Peugeot 807
• Peugeot Partner III / Rifter
• Peugeot 508
• Various DS, Opel, Fiat and Toyota models where the same relay reference is used

Installation Recommendation

• Always disconnect the vehicle battery before working on electrical components to avoid short circuits and accidental deployment of safety systems.
• Locate the relay in the vehicle’s relay/fuse box or seat control area. Access may require removal of seat trim or under-dash panels depending on model.
• Remove the old relay by unplugging the electrical connector and releasing any retaining clips or screws. Compare part numbers and connector shapes to ensure correct replacement.
• Fit the new relay in the same orientation, secure any clips, reconnect the wiring and reassemble trim panels.
• Reconnect the battery and verify seat heating function through vehicle controls. Check for blown fuses or error codes if heating does not operate as expected.
• For vehicles with body control modules that manage seat functions, confirm that the relay socket and wiring are free from corrosion or damage before installation.

Most Common Failure Reasons

• Contact Wear: Repeated switching cycles cause pitting and increased contact resistance, leading to intermittent operation or overheating.
• Corrosion and Moisture: Water ingress or condensation in relay housings and connectors causes poor electrical contact and eventual failure.
• Overcurrent Stress: Faulty seat heating elements or wiring shorts increase current draw and can weld relay contacts or damage the relay housing.
• Connector Issues: Loose, oxidised or damaged sockets and pins create heat build-up and unreliable performance.
• Age and Thermal Cycling: Long-term exposure to heat and vibration accelerates internal fatigue of relay internals.

Practical Tips

• When replacing the relay, inspect fuses, wiring harness, seat heating element continuity and connector condition to prevent repeat failures.
• Keep the contact area dry and apply dielectric grease to connectors if appropriate to reduce corrosion risk.
• Search by OE numbers (9673891680 / 4539528 / 6509ER) to quickly find the correct part for your vehicle.

This relay is intended for experienced fitters and DIY mechanics familiar with automotive electrical systems. Proper diagnostics prior to replacement helps ensure the underlying cause is resolved and avoids unnecessary part changes.