2003 - 2008 BMW Z4 HID Headlight Ballast (OEM)

What to Look For When Buying:

• Compatibility: Ensure the ballast is designed for your vehicle's make, model, and year.
• Warranty: Check for a warranty period to protect against defects.
• Reputation: Buy from a reputable seller known for quality parts.
• Condition: Understand the difference between used, refurbished, and new aftermarket options.

Quality Indicators:

• OEM Markings: Original Equipment Manufacturer (OEM) parts often have manufacturer markings.
• Testing: Used and refurbished parts should be tested to ensure proper function.
• Construction: Look for solid construction and quality materials.

What's Typically Included:

• The HID headlight ballast unit itself
• Sometimes mounting hardware (check with the seller)
• Installation instructions (sometimes, but often not included)

Difficulty Level and Estimated Time:

• Difficulty: Intermediate
• Estimated Time: 30 minutes to 1 hour per side

Special Tools Needed:

• Socket set
• Screwdrivers (Phillips and flathead)
• Pliers
• Multimeter (optional, for testing)

Critical Steps and Tips:

1. Disconnect the battery: Always disconnect the negative battery terminal before working on electrical components.
2. Locate the ballast: The ballast is usually located near the headlight assembly.
3. Remove the old ballast: Disconnect the wiring harness and remove any mounting screws or clips.
4. Install the new ballast: Connect the wiring harness and secure the ballast with the mounting hardware.
5. Test the headlight: Reconnect the battery and test the headlight to ensure it's working properly.

DIY or Professional Installation:

• DIY is possible for mechanically inclined individuals.
• Professional installation is recommended if you are not comfortable working with electrical systems or if you lack the necessary tools.

Compare:

Used OEM:

• Best value option.
• Genuine factory parts, ensuring proper fit and function.
• Tested and inspected to meet quality standards.
• Significantly lower prices compared to other options.

Refurbished OEM:

• Factory parts that have been professionally restored.
• May include replacement of common failure components.
• Offers a balance of quality and cost.

New Aftermarket:

• Brand new parts manufactured by third-party companies.
• Built to meet or exceed original equipment specifications.
• Widely available.

Parts Commonly Replaced or Checked:

• HID headlight bulbs
• Headlight wiring harness
• Headlight fuses
• Igniter (sometimes integrated with the ballast)

Why Replace Related Parts:

• Replacing worn or damaged bulbs can prevent premature ballast failure.
• Checking the wiring harness ensures proper voltage delivery to the ballast.
• Addressing underlying electrical issues can prevent repeat failures.

How Long This Part Normally Lasts:

• Typically 5-10 years.

Factors That Affect Longevity:

• Quality of the original part
• Operating conditions (climate, road conditions)
• Voltage fluctuations
• Bulb condition
• Water intrusion

Budget vs Mid-Range vs Premium Options:

• Used OEM: $50 - $150
• Refurbished OEM: $100 - $250
• New Aftermarket: $80 - $300

Labor Cost Considerations:

• Professional installation typically costs $50 - $200, depending on the shop and vehicle.

Total Job Cost Estimates:

• DIY: $50 - $300 (parts only)
• Professional Installation: $100 - $500 (parts and labor)

• Some vehicles are known to have issues with water intrusion into the headlight assembly, which can damage the ballast.
• Certain models may have specific diagnostic codes related to ballast failure.
• Check for any Technical Service Bulletins (TSBs) related to headlight issues for your specific vehicle.
• Some Audi models are known to have issues with the ground connections for the headlights, which can cause ballast failure.

How to Confirm Proper Operation:

• Turn on the headlights and verify that both headlights illuminate brightly and consistently.
• Check for any flickering or unusual colors.
• Observe the headlight beam pattern to ensure proper alignment.

What to Look/Listen For:

• Headlights should turn on immediately without delay.
• There should be no buzzing or hissing sounds coming from the ballast.
• No error messages should appear on the dashboard related to the headlights.

Q: How do I know if it's the ballast or the bulb that's bad?
A: The easiest way is to swap the bulbs between the left and right headlights. If the problem moves to the other side, the bulb is bad. If the problem stays on the same side, it's likely the ballast.

Q: Can I replace just one ballast, or do I need to replace both?
A: You can replace just one ballast if the other one is still working properly. However, it's often recommended to replace both at the same time to ensure consistent performance and color.

Q: Are aftermarket ballasts as good as OEM ballasts?
A: Aftermarket ballasts can be a good option, but quality can vary. Look for reputable brands and check reviews before purchasing. OEM ballasts are generally considered to be more reliable.

Q: What happens if I install the wrong ballast?
A: Installing the wrong ballast can damage the headlight system or cause the headlights to not function properly. Always ensure that the ballast is compatible with your vehicle's make, model, and year.

Q: Is it safe to drive with a bad headlight ballast?
A: Driving with a malfunctioning headlight is unsafe, especially at night or in low-visibility conditions. Replace the ballast as soon as possible to ensure proper visibility.

OEM Part Numbers:

• Audi: 4E0907476
• BMW: 63126907488
• Chrysler: 05103359AA
• Dodge: 5103359AA
• Ford: 2M5Z13C170AA
• Hella: 5DV00829000
• Jaguar: C2S15079
• Land Rover: YWC500430
• Mercedes-Benz: 0028202326
• Saab: 12790592

Fits Years: 2003 2004 2005 2006 2007 2008