1T0955978A Volkswagen CYLINDER

Basically, it regulates the voltage going to your HID or xenon headlight bulb. Think of it as a gatekeeper, making sure the bulb gets just the right amount of power to ignite and stay lit. It starts with a low voltage to kick things off, then ramps it up and holds it steady. It also limits the current, preventing the bulb from drawing too much power and burning out. It sits between your vehicle’s electrical system and the headlight bulb. It takes the 12 – volt power from your car and transforms it into the much higher voltage the HID bulb needs – usually somewhere around 20,000 volts for a brief moment to start the arc. After that, it maintains a consistent current to keep the light shining brightly. You’ll usually find one ballast per HID bulb, so if you have HID headlights, you’ve got at least two of these things. Well, without a functioning ballast, your HID headlight won’t turn on, or it might flicker, be dim, or just quit working altogether. It’s a safety thing, obviously – driving with one headlight out is a problem. Also, a failing ballast can actually damage the bulb itself, so it’s best to replace it when you notice issues. If you’re seeing inconsistent light, or the bulb keeps blowing, the ballast is often the culprit. You can find a replacement for pretty much any vehicle on sites like Fixparts Online, and it's usually a straightforward repair. You'll notice if this part goes bad, the headlight will definitely be acting up. Your satisfaction is our priority: Cylinder (MPN 1T0955978A) includes a 12-month warranty!

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• Get parts made specifically for your VW, ensuring a perfect fit and reliable performance. • Volkswagen parts are quality-tested to meet high standards, so you can drive with confidence. • Using genuine VW parts helps maintain your vehicle’s value. • We have a wide selection of parts, from everyday maintenance items to more complex components. FixParts Online – Your Trusted Source for Quality Volkswagen Auto Parts.