Xenon Box, Ballast ( Headlight Control Module ) A,B,C,CLA,GLA,SLK,ML,GL / W176, W246, W117, X153, W172, W166, X166

When High-Intensity Discharge (HID) lighting stops working, the root cause is almost always either a spent bulb or a burned-out ballast. Xenon ballasts typically fail due to internal component ageing, voltage spikes, or moisture ingress resulting from cracked headlight casings and degraded housing seals. At M&B Parts, we supply OEM-specification replacement ballasts designed to restore crisp, reliable beam output across your vehicle's factory headlights.

What Is a Xenon Ballast?

A Mercedes-Benz xenon ballast is the core power management hub for an HID lighting system. While standard halogen bulbs run continuously on the vehicle's 12V direct current, xenon gas capsules require an initial surge of up to 25,000 volts to ignite an electrical arc between two electrodes.

Once lit, the ballast immediately steps down and precisely regulates operating power to approximately 85V AC. This continuous regulation prevents flickering, protects sensitive vehicle electrical parts, and prevents bulb burnout.

Troubleshooting tip: before ordering a replacement, swap the existing xenon bulb over to the working headlight on the opposite side. If the bulb illuminates normally, the bulb is intact and the original ballast unit requires replacement.

Features & Specifications

Our replacement ballasts match original factory dimensions and connector pinouts, for seamless communication with your onboard CAN bus system without triggering dashboard warning lights.

• OEM-Matched Performance: designed to match original equipment reference units, including popular OE reference numbers such as A1669002800 (A 166 900 28 00), covering W204, W211, W212 and W221 platforms.
• Sealed Aluminium Construction: housed in a die-cast, weather-sealed aluminium casing that dissipates thermal heat and protects delicate circuitry against road grime and water penetration.
• Integrated Safety Circuitry: built-in protections guard against open circuits, short circuits, reverse polarity and sudden alternator voltage spikes.

Note: while replacement is plug-and-play, ballasts are commonly mounted to the underside of the headlight assembly. On certain chassis, accessing the mounting screws requires partially loosening the front bumper panel.

Technical Specifications

Why Buy Your Xenon Ballast from M&B Parts

• Aftermarket Mercedes-Benz Specialists: we stock an extensive selection of chassis-specific control modules and complete Mercedes-Benz headlight units.
• Save Over Dealer Pricing: gain reliable, flicker-free ignition and OEM-grade beam stability at a fraction of typical dealer pricing.
• Fast Dispatch Across South Africa: in-stock units are quickly dispatched via tracked courier directly to your door or workshop.

Frequently Asked Questions

How do I know if my Mercedes xenon ballast is faulty?
If your xenon headlight doesn't turn on and swapping the bulb to the other side doesn't fix the problem, the ballast on the affected side has likely failed and needs replacement.

Are xenon ballasts interchangeable between Mercedes models?
Xenon ballasts are model-specific. You must match the ballast part number to your Mercedes-Benz chassis code, for example W212, W204 or W211, and production year to ensure compatibility.

What is the difference between D1S and other xenon ballast types?
D1S refers to the xenon bulb type. D1S ballasts are designed to provide the specific high voltage required to ignite and run D1S bulbs, used in many Mercedes-Benz xenon headlight systems.

Is this a genuine Mercedes-Benz ballast?
No. This is a high-quality aftermarket ballast built to OEM specification, not a genuine Mercedes-Benz part.