O-NEX Xenon D1S D3S 35W HID Ballast 8K0941597 Factory Replacement

In this review the O-NEX Xenon D1S D3S 35W HID Ballast is evaluated as a practical, low-cost replacement option for specific Audi and Volkswagen headlights. The bottom line: it is a plug-and-play control module intended for owners who need a direct replacement for a failed factory ballast and want a quick, low-effort swap. The reviewer found it most compelling for its compatibility with several OEM numbers and easy installation when the factory connector and housing match exactly.

Key Features

• Direct replacement design: The unit is built to match factory form and connector layout so it installs without rewiring when it matches the original ballast.
• OEM number compatibility: It lists multiple OEM numbers (including 8K0941597 variants) so buyers can confirm fit with their factory part number before purchase.
• Plug-and-play convenience: For vehicles with the identical connector and ballast style this module restores headlight function with minimal tools or expertise.
• Single-piece pack: Sold as one replacement unit which keeps the purchase straightforward when only one ballast needs swapping.
• Wide vehicle fit range: Coverage includes several Volkswagen, Audi, and Bentley models across model years, reducing the chance of ordering the wrong type when verified.

Who It's For

The ballast suits DIYers and independent repair shops replacing a failed factory ballast on supported Volkswagen, Audi, or Bentley models where the connector and housing match the pictured unit. It is helpful when the original ballast has failed but the headlight housing remains dry and intact.

It is not the best choice for someone whose headlight housing has water damage or repeated sealing issues, because replacement ballasts can fail again if moisture is present. Buyers uncertain about their connector type or with mid-cycle vehicle changes should verify the part visually before ordering or consult a dealer for exact fitment.

Pros & Cons

Pros

• Direct-fit, plug-and-play design simplifies installation when the connector matches.
• Covers multiple OEM numbers, making it straightforward to match to factory parts.
• Good value for a single replacement ballast compared with dealer pricing.

Cons

• Mixed reliability reported by users; some experience early failure so longevity may vary.
• Will not solve failures caused by water in the headlight housing and may fail again if moisture persists.

Specifications

Brand	O-NEX
Type	35W HID ballast control module
OEM numbers	8K0941597, 8K0941597B/C/E, W003T20171, W003T22071, BAM92-143700
Pack quantity	1 piece
Compatible bulbs	D1S, D3S
Fitment highlights	Volkswagen, Jetta, Golf, Polo, Touareg, Audi and Bentley Continental GT (verify years and connector)

Our Verdict

The O-NEX Xenon D1S D3S ballast is a sensible, cost-effective replacement for owners who confirm an exact connector and ballast match with their factory unit. It offers plug-and-play convenience and broad OEM compatibility, but buyers should inspect for water ingress and be aware that some users report variable longevity. For a dry, correctly matched headlight it represents good value compared with sourcing a dealer unit.

Frequently Asked Questions

Will this ballast fit my car?
Check your factory ballast connectors and the OEM number listed; the unit fits only if the connector and housing style match exactly.

Does it come as a pair?
No, this product is sold as a single replacement ballast unit (pack of 1).

What causes most ballast failures?
The most common cause is water in the headlight housing; replacing the ballast without addressing moisture may lead to repeat failures.