As vehicles age, washer nozzles can become clogged or damaged due to exposure to various environmental factors such as dirt, road salt, and extreme temperatures. Regular inspection and replacement of the rear washer nozzle is recommended to maintain efficient vehicle operation, particularly in regions with harsh weather conditions.

Replacing the rear windshield washer nozzle is straightforward and typically involves removing the existing nozzle from its mounting, disconnecting the washer fluid line, and replacing it with the new nozzle. This procedure helps ensure a clear view while driving, enhancing safety.

Technical Information

• Manufacturer: PSA Citroën Peugeot
• Model: Citroën C4 Coupe (First Generation)
• Product Codes: 6438P9
• Additional Numbers: NFP

Overview

This rear wiper motor is designed for Citroën C4 and C4 Grand Picasso models and is commonly referenced by part numbers 0390201807, 9646803180 and 6405S2. It provides reliable wiping action for the rear window, restoring visibility and passenger safety. Ideal for professional workshops and competent DIY mechanics who search by OE number to find the correct replacement quickly.

Features & Benefits

• Direct fit for specified Citroën/Peugeot tailgates — designed to match factory mounting points and connector types.
• Robust electric motor with integrated reduction gearing for consistent wiping torque.
• Easy replacement procedure: accessible from tailgate interior, minimal disassembly for fast workshop turnaround.
• Commonly sought by OE reference — convenient for inventory management and quick identification.

Technical Information

• Manufacturer: Stellantis (Citroën / Peugeot)
• Model: Citroën C4; Citroën C4 Grand Picasso
• Product Codes: 0390201807, 390201807
• Additional Numbers: 9646803180, 6405S2

Installation Recommendations

Recommended for experienced mechanics and capable DIYers. Follow these general steps:

• Park vehicle on level ground and disconnect the negative battery terminal before starting any electrical work.
• Open tailgate and remove the inner trim panel to access the wiper motor and linkage (retain fasteners and clips for reassembly).
• Remove the wiper arm (remove the cover, then the retaining nut) and position it safely aside.
• Disconnect electrical connector to the motor, then unbolt the motor assembly from the tailgate and detach it from the linkage.
• Fit the replacement motor, attach linkage, bolt to specified torque, reconnect the electrical connector and refit the wiper arm in the correct park position.
• Reconnect the battery and test full travel of the rear wiper to ensure correct park position and operation.

Common Failure Reasons

• Water Ingress And Corrosion: Tailgate seals can fail or moisture can penetrate the motor housing, causing corrosion of contacts and gearing.
• Wear Of Brushes Or Commutator: Over time, brush wear reduces motor efficiency and eventually stops the motor.
• Gear Or Linkage Wear: Plastic or metal reduction gears and linkage joints can strip or seize under load (ice or heavy debris).
• Electrical Issues: Corroded connectors, broken wiring or blown fuses can mimic motor failure — always check power and ground first.
• Mechanical Overload: Frozen wiper blades or excessive resistance can overload the motor and damage internal gears.

Practical Tips

• Before replacing the motor, verify supply voltage and ground at the connector and check the fuse for the rear wiper circuit.
• Inspect and lubricate linkage pivot points where appropriate; replace worn linkage clips to prevent premature wear of a new motor.
• When refitting the wiper arm, ensure the correct park position to avoid scuffs and to guarantee full wipe coverage.

Why Choose This Part

If you are replacing a failed rear wiper motor on a Citroën C4 or C4 Grand Picasso, selecting a unit that matches the OE references above ensures correct fitment and straightforward installation. This part is suitable for workshops that keep stock by part number and for enthusiasts who prefer to source components by OEM codes.