This high-quality replacement switch is designed to restore reliable control of the rear window defogger on Citroën Berlingo II and Peugeot Partner II models. Ideal for professional mechanics and competent DIYers, the switch is commonly searched and identified by the reference numbers 9644851077 and 6554AF. The unit provides positive tactile feedback, integrated illumination for nighttime use and straightforward plug-and-play replacement in most installations. Replacing a faulty switch quickly brings back rear-window demisting functionality, improving visibility and safety in wet or frosty conditions.

Technical Information

• Manufacturer: Stellantis (Citroën / Peugeot)
• Model: Citroën Berlingo II; Peugeot Partner II
• Product Codes: 9644851077, 6554AF
• Other Numbers: 6554AF | 9644851077

Function And Application

The switch controls the rear window heating (defogger) circuit, typically energizing the rear heated-glass element via a dedicated relay and fuse. It also usually contains an indicator lamp or LED to show when the grid is active. This switch is intended for dashboards and control panels original to Citroën Berlingo II and Peugeot Partner II vehicles where the listed reference numbers match.

How To Replace

1. Disconnect The Battery Before Starting Work To Avoid Short Circuits And Protect Vehicle Electronics.
2. Remove The Trim Surrounding The Switch Using Appropriate Trim Tools To Prevent Damage.
3. Release The Switch From The Panel (Usually Retained By Clips) And Pull It Out Gently.
4. Disconnect The Wiring Harness Connector From The Rear Of The Switch.
5. Fit The Replacement Switch, Reconnect The Harness And Test Rear Heater Operation Before Reassembling Trim.

Installation Recommendations

• Always Disconnect The Battery Before Demounting Or Mounting The Switch.
• Inspect Connector Pins And Wiring For Corrosion Or Damage; Clean Contacts And Apply A Small Amount Of Dielectric Grease If Suitable.
• Check Related Fuses And The Rear-Window Heater Relay If The New Switch Does Not Activate The Grid—Failure Is Not Always The Switch.
• Ensure Proper Fitment And Orientation When Pressing The New Switch Into The Panel To Avoid Breaking Retaining Clips.

Most Common Failure Causes

Failures Usually Result From Worn Electrical Contacts Or Burnt Traces Caused By High Current Switching Over Time. Other Typical Causes Include Moisture Ingress Into The Connector Or Switch Housing, Mechanical Wear Of The Actuation Mechanism, And Failed Internal Illumination (Bulb Or LED). In Some Cases The Switch Appears Dead But The Real Issue Is A Blown Fuse Or A Faulty Relay In The Defogger Circuit.

Notes For Professionals And Enthusiasts

• Reference Numbers 9644851077 And 6554AF Are Frequently Used By Customers When Searching For This Part — Including These In Product Listings Improves Findability.
• Test The New Switch Immediately After Installation To Confirm Correct Operation Of The Rear Heater And Indicator Lamp.
• Keep The Vehicle Manual Or Wiring Diagram Handy When Diagnosing Related Electrical Issues.

Warranty And Quality

Supplied As A Direct-Fit Replacement Intended To Match Original Functionality. Suitable For Workshop Use And DIY Repairs Where Reference Numbers Match The Vehicle Requirement.

Product Overview

This original-style rear window heating (rear window defogger) switch is made for small city cars from the Toyota/PSA collaboration. It provides a reliable, simple interface to activate the rear window heater, restoring clear visibility and removing condensation or light frost quickly. Ideal for professional technicians and DIY enthusiasts who search by part number (84790-0H010 / 654612).

Function And Application

The switch completes the control circuit for the rear window heating element and usually supplies a signal to the rear defogger relay. It is mounted in the dash or center console area and operates by pressing the button to engage the heater. Typical symptoms of a faulty switch include no response when pressed, intermittent activation, or loss of button illumination.

Compatibility

Fits First Generation models produced in the Toyota/PSA joint platform, for example:

• Citroën C1 (First Generation)
• Peugeot 107 (First Generation)
• Toyota Aygo (First Generation)

Technical Information

• Manufacturer: Stellantis (Citroën / Peugeot)
• Model: Citroën C1, Peugeot 107, Toyota Aygo (First Generation)
• Product Codes: 84790-0H010
• Additional Numbers: 654612, 84790-010

Installation Recommendations

Follow safe work practices when replacing electrical switches. Recommended steps:

• Disconnect the negative battery terminal before starting any work on the vehicle electrical system.
• Use trim removal tools to remove dash/console panels without damage.
• Release the switch retaining clips and carefully extract the switch from the panel.
• Unplug the electrical connector and inspect terminals for corrosion or bent pins.
• Fit the new switch, reconnect the connector and reassemble panels. Reconnect the battery and test the rear window heater function and switch illumination.

Useful tools: plastic trim tools, small screwdriver, multimeter for continuity checks, and a flashlight.

Why This Part Fails Most Often

• Mechanical Wear: Repeated use can wear internal contacts or springs, causing intermittent operation.
• Corrosion and Moisture Ingress: Exposure to moisture or condensation can corrode contacts and connectors.
• Electrical Overload Or Faults: Upstream faults (bad relay, wiring short, or blown fuse) can stress the switch or its illumination lamp/LED.
• Illumination Failure: The internal lamp or LED that lights the switch can burn out while the switch mechanism remains functional.

Practical Tips For Diagnosis

• Check fuses and the rear defogger relay first—symptoms attributed to the switch are often caused by these components.
• Measure continuity across the switch terminals with a multimeter when pressing the button to confirm operation.
• Inspect connector pins for bending or corrosion and clean contacts if necessary.

Durability And Maintenance

There is no fixed replacement interval; a switch can last many years under normal conditions. Replace the switch if you notice stiffness, intermittent function, complete failure, or loss of illumination. Regular inspection of connectors and ensuring seals around dashboard openings help extend service life.

Typically, this controller has a lifespan that may vary depending on usage and environmental conditions. However, like many electrical components, it can fail due to wear and tear, consistent exposure to moisture, or electrical issues within the vehicle. Therefore, regular checks are advisable, especially during seasonal changes, to ensure optimal functionality.

Replacing the Rear Window Heating Controller is straightforward and can typically be done with basic tools. Ensure that the vehicle’s electrical system is disconnected before performing any installation to prevent accidents.

Technical Information

• Manufacturer: PSA
• Model: Citroën Xsara and others
• Product Codes: 655497
• Other Numbers: NFP

This essential component operates the heating elements in the rear window, ensuring maximum visibility during cold weather conditions. It is crucial for maintaining safety while driving in adverse weather. Over time, the controller can wear out due to constant use, so it is advisable to replace it if you notice any dysfunction or delay in heating the rear window.

Regular maintenance of this part is recommended to ensure optimal performance during winter months or in colder climates.

Technical Information

• Manufacturer: PSA
• Model: Citroën Berlingo I, Peugeot Partner I
• Product Codes: 655492, 6552PJ
• Additional Numbers: 6552PJ, 655492