Description
Glow Plug Relay CARTIER. Used part with functional warranty.
This Cartier glow plug relay is designed for diesel preheating circuits on several Citroën and Peugeot models. It switches and supplies the high current required by glow plugs to shorten cold-start time and improve combustion during engine warm-up. The relay is commonly searched under product codes 9640469680 and 598140 — including these numbers in searches increases the chance of finding the correct replacement quickly.
Technical Information
- Manufacturer: Cartier
- Model: Citroën C4 Picasso, Citroën C5, Citroën C8, Peugeot 307, Peugeot 807
- Product Codes: 9640469680, 598140
- Other Numbers: 598140, 9640469680
Function And Typical Symptoms
The glow plug relay controls the timing and power supply to the glow plugs, usually under command from the engine control unit. When the relay fails, common symptoms include difficult cold starts, extended cranking, the glow-plug/warning lamp behaving erratically or not lighting, rough idling after cold start and increased white or grey smoke on cold starts.
How To Replace
- Disconnect the negative battery terminal before work to avoid short circuits.
- Locate the relay in the engine bay—typically in the fuse/relay box or mounted near the glow-plug wiring harness.
- Release electrical connectors and any retaining clips or screws, then remove the old relay.
- Fit the replacement relay in the same orientation, secure fasteners and reconnect the electrical plugs firmly.
- Reconnect the battery and perform a function check: turn the ignition to the preheat position and verify the glow-plug lamp and engine start behaviour.
- If starting problems persist, inspect glow plugs, wiring and related fuses for faults or excessive current draw.
Installation Recommendations
- Use basic workshop tools and observe anti-static and anti-short precautions when handling electrical parts.
- Ensure connector pins are clean and free of corrosion; apply dielectric grease if appropriate to improve contact and prevent future corrosion.
- Always check associated fuses and the condition of the glow plugs — a failed glow plug can overload the relay and shorten its life.
- Verify secure mounting and correct orientation to avoid vibration-related failures.
Most Common Failure Causes
- Contact Wear And Pitting: Repeated high-current switching causes contacts to wear or stick.
- Thermal Stress: Continuous heating and cooling cycles lead to internal degradation.
- Corrosion And Moisture Ingress: Water or road salt can corrode terminals and housing.
- Overload From Faulty Glow Plugs: Shorted or high-resistance glow plugs increase current draw and accelerate relay failure.
- Age And High Mileage: Electrical components degrade over time, especially on vehicles with intensive cold-start cycles.
This used Cartier glow plug relay is a practical replacement for workshop technicians and DIY enthusiasts repairing the preheat system on compatible Citroën and Peugeot diesel models. Always match the product codes (9640469680 / 598140) when selecting the part to ensure correct fitment.
