AudiWorld Forums

Audi A6 C5: How to Install HID Headlights

This article will walk you through the process of an HID headlight installation for the A6 C5.

By Brett Foote - April 7, 2016

This article applies to the Audi A6 C5 (1998-2004).

The benefits of High Intensity Discharge (HID) lighting are well known by most automotive enthusiasts – they are two to three times brighter than halogens, provide a cool white glow that looks great, and it takes less power to run them. While HID lights have largely been replaced as the trendy ones to put on new cars by LED lighting, they offer many of the same benefits but at a much lower cost. And that, coupled with their superior brightness (at least for now) is why HID conversions remain popular on older, halogen-equipped cars. If you want to add some serious power to your headlights, here's how to get it done.

Audi A6 How to install HID headlights infographic

Materials Needed

  • HID bulbs
  • Mounting ballasts
  • Power cables
  • Zip ties
  • Torx driver and bits
  • Drill and drill bits

Step 1 – Remove headlights

To gain access to the passenger side headlight for removal, you must first remove a couple of parts.

  • Open the hood and pull off the plastic cover that sits on top of the air filter assembly.
  • Pull the front air inlet hose out. Now you will be able to access the passenger side headlight.
  • Remove the three bolts on top of the headlight and disconnect the harness on the back.
  • To remove the driver's side headlight, simply remove the three bolts on top and disconnect the harness from the back.
  • Remove the front air inlet hose.
    Figure 1. Remove the front air inlet hose.
  • Remove the three bolts from the passenger side headlight.
    Figure 2. Remove the three bolts from the passenger side headlight.
  • Remove the three bolts from the driver's side headlight.
    Figure 3. Remove the three bolts from the driver's side headlight.

Step 2 – Install HID bulbs and ballasts

  • Drill a hole in the bottom of the headlight or headlight cap big enough to feed the wiring through.
    • Drill a hole for the new wiring.
    Figure 4. Drill a hole for the new wiring.
  • Remove the halogen bulbs and install the HID bulbs in their place.
    • Install the HID bulbs.
    Figure 5. Install the HID bulbs.
  • Feed the wires through the hole you drilled and make sure the grommet is nice and tight to prevent any condensation from getting in.
    • Feed the wiring through the drilled hole.
    Figure 6. Feed the wiring through the drilled hole.
  • Screw the ballast into the bottom of the headlight assembly and plug in the wires.
  • Connect the ballast wiring to the car's harness and test to make sure everything's working properly.
  • Reinstall the headlights and screws, then reinstall the front air inlet hose and cover.
Install the ballasts and wire everything up.
Figure 7. Install the ballasts and wire everything up.

Related Discussions and Video