ROYUAN Clock Spring A6394640718 for Mercedes-Benz W639 Vito / Viano / V-Class (2003-2014) – Airbag Squib
ROYUAN
Premium Aftermarket Auto Parts – Safety & Reliability
Product Description – ROYUAN Clock Spring A6394640718 for Mercedes-Benz W639 Vito / Viano / V-Class (2003-2014)
🔍 IMPORTANT – PLEASE READ
This ROYUAN clock spring (also called airbag squib or contact spiral) is a critical safety component behind the steering wheel. It ensures continuous electrical connection for the driver's airbag (SRS), horn, and multi-function steering wheel controls as the wheel turns.
⚠️ CRITICAL: This part number has NOT been verified in our catalogs. Fitment is not guaranteed without physical comparison. Always visually compare the connector shape, number of pins, and overall appearance with your original part before ordering. For 100% confirmation, contact us with your VIN or clear photos of your original clock spring.
OEM Reference (Unverified): A6394640718.
Return Policy: This electrical component is not returnable once installed. Please ensure compatibility before purchase.
Compatible Vehicles
| Make | Model | Years | Notes |
|---|---|---|---|
| Mercedes-Benz | Vito / Mixto (W639) | 2003–2014 | 2.2 CDI / 3.0 CDI / 3.2 / 3.5 / 3.7, with driver airbag |
| Mercedes-Benz | Viano (W639) | 2003–2014 | 2.0 CDI / 2.2 CDI / 3.0 CDI / 3.2 / 3.5, with driver airbag |
| Mercedes-Benz | V-Class / 唯雅诺 (W639) | 2004–2015 | 2.5L / 3.0L / 3.2L / 3.5L, verify steering wheel controls |
| Mercedes-Benz | Vito Bus (W639) | 2003–2014 | Passenger van variant, same steering column |
| Mercedes-Benz | Viano Fun / Marco Polo (W639) | 2003–2014 | Camper/leisure variants, verify connector |
Technical Specifications
- Brand: ROYUAN – Premium aftermarket manufacturer
- Function: Clock spring / Squib / Contact spiral
- Placement: Steering column, behind steering wheel
- Material: High-strength copper ribbon, flame-retardant ABS plastic housing
- OE Number (Reference): A6394640718
Key Functions
✅ Airbag (SRS) system activation – critical safety component
✅ Horn operation
✅ Multi-function steering wheel controls (if equipped)
Signs of Failure
⚠️ Airbag/SRS warning light on dashboard
📢 Horn does not function
🎛️ Steering wheel controls unresponsive
🔊 Clicking noise when turning
🚨 Driver airbag may not deploy in collision
⚠️ IMPORTANT SAFETY NOTE & INSTALLATION TIPS
Before Installation: Disconnect battery negative terminal and wait at least 10 minutes for airbag discharge. Follow Mercedes-Benz safety procedures.
Centering: Keep front wheels straight. Do NOT remove centering clip until fully installed. If needed, turn rotor clockwise to stop, then back approximately 2.5 turns to center.
Verification: Compare connectors/pins with original. Provide VIN or photos for confirmation. W639 may have different variants – verify before ordering.
Post-Installation: Test horn, steering controls, and ensure SRS warning light turns off. Use diagnostic tool to clear faults if required.
Professional Installation: Strongly recommended due to airbag system risks.
Quality You Can Trust
- High-purity copper ribbon – stable signal transmission
- Flame-retardant housing – safety certified
- 300,000-cycle endurance test (-40 °C to +85 °C)
- Centering clip included – do not remove early
- 1-year warranty
Package Includes: 1 x ROYUAN Clock Spring Assembly (with centering clip), installation guide on request.
